Small Block & Big Block Chevy Specific - possible to make a 305 fast?

I just got an 83 TA with a brand new 305. I put it in myself :), and we all know that the 80' TA's with 305's put out about the same HP as a new 4cyl civic. I am going to build this shit out of it, but is 305ci just to little to get lots of power, or not a problem. Im lookin to get like min 500-600 hp.

Also im wanting to make it a really high reving motor, so can anyone link me to a cam that has like a at least an 8k redline?

I just got an 83 TA with a brand new 305. I put it in myself :), and we all know that the 80' TA's with 305's put out about the same HP as a new 4cyl civic. I am going to build this shit out of it, but is 305ci just to little to get lots of power, or not a problem. Im lookin to get like min 500-600 hp.

Also im wanting to make it a really high reving motor, so can anyone link me to a cam that has like a at least an 8k redline?

350 blocks are still a dime a dozen. I suggest getting one if you can. although it is possible to make a 305 run good. The only draw backs are less cubes, and you are kinda restricted on valve size.

The first motor I modified was the stock TBI 305 in my 1992 Camaro. I got my hands on a older set of 305 heads (perimeter valve cover bolts), and I believe they had a slightly smaller chamber than the heads on my 305 TBi motor. Most likely the same thing you have on your 83. Anyways did a half ass port job to the heads in my garage, port matched the intake and exhaust ports to the gaskets I was going to use, smoothed out the bowls and chambers, stuffed a 1.94 intake valve in the head, and unshrouded the intake valve. Comp Cams 236/236 @ .050 .454/.454 llift hydraulic cam (biggest cam I could get that still required the stock diameter valve springs).
Weiand single plane X-celerator intake, Holley 650 double pumper. Proform 1.6 roller rockers. All of this on top of a 130,000 mile tired out stock 305.
4.10 Gear, 5 speed manual trans 3400 lb car went 13.0's on motor and 11.89 on a 150 shot.

You can put a stroker crank in a 305 block and make a 337 I believe.

damn sounds like you put alot of work into it. So im pretty much stuck in the perameters of there's no replacement for displacement phrase....isnt every small block the same, the only dif is the bore and stroke? so could i stroke the shit out of it, and bore it paper thin, and make a 406 or a 427?

damn sounds like you put alot of work into it. So im pretty much stuck in the perameters of there's no replacement for displacement phrase....isnt every small block the same, the only dif is the bore and stroke? so could i stroke the shit out of it, and bore it paper thin, and make a 406 or a 427?


All small blocks are not created equally, the 305 block is not the same as a 350 block. You cant bore a 305 to much or you'll run right into the water passages, and your walls would be to thin for some real power.

Im not sure what magazine did it but they got around 425hp out of a stock 305 with a holley top end kit. Just go that route if you cant dish out some cash for a used 350 block. Or grab a 400 block and you can see sizes around 455 with sleeves.

it is like any other small block, a good cam/head/intake combo and you have it made. which 305 is it? LG4 or L69? the L69 has better heads and a little better cam stock, but if you are planning a build up that isn't very significant.
the biggest draw back to the stock 3rd gen and replacement 305's is that the cams are total jokes, many aren't even .400 lift at the valve. look into a performer/street dominator intake and a good cam that revs to around 5500, comp extreme energy or lunati voodoo cams are recomended since they have modern ramp designs that help build cyl pressure and allow you to avoid spending a bunch of cash and effort doing a head swap.

Turbocharger(s).

Turbocharger(s).

H/C/I and then slap a single or twin turbo setup on it. You can spin it to the moon and make some really good power.

have you thought of selling the 305 since it is still good and trying to buy something like a 350/400 and starting from there?305 engines aren't really a good starting point.

unless you have no choice but to keep the 305 you shouldn't keep it
the small bore limits power
if you want to build something that is fun to drive and gets good mileage then it's not a terrible choice

note that Chevy High Performance magazine is doing an '84 Z28 atm, they did heads/cam/edelbrock headers and got around 200 rwhp (not bad for a 305 and CA emissions)

conventional wisdom would say 350 or bigger (383s are relatively cheap now)
big blocks fit in 3rd gens nicely too :devil:

Id love to get a 400 or bigger block, the only reason I would hessitate to getting rid of the 305 is that i put it in about 3 years ago, and only has a max of 50 miles on it to this date. Im not sure which engine it is, i got it from oreily's if id have to bet id say the LG4. I would love to put a big block in it, but arent they pretty expensive to modify? Turbos are a good idea. Does anyone think i could get my money back out of the engine if i decide to swap for a bigger block? It cost me somewhere in the neighborhood of $1,200 for the engine, and new parts.

yeah but for 1300 you could get a 300hp gm 350.

Where did you get that price at

check pace performance

imo, sell the 305 and put a 350 in it.. if im correct, youll be able to hit that 8k rpms you want a lot easier in a small block than a big block without damaging the block.

you might want to check out www.GAFBA.com there is a member there who has done LOADS with a 305..getting it to run 12.0's all motor i beleive although i dont know his rpm's or what all was done to it..but it is Definately worth a look!!!

ok ill check it out. My gf's parents have an old caddy with i think a 472 BB in it. Could i rip that sucker out and build it? Someone told me that those caddy engines are shit to build and probly wouldnt even fit in my car is that true, or BS?

damn sounds like you put alot of work into it. So im pretty much stuck in the perameters of there's no replacement for displacement phrase....isnt every small block the same, the only dif is the bore and stroke? so could i stroke the shit out of it, and bore it paper thin, and make a 406 or a 427?

Safely you could bore it .060, but you still may have some cooling issues. But honestly what will that get you a 310 cube motor ? or a 347 if it has an arm in it.

As for selling the 305, good luck, I can't even give away the 2 I have. Nobody wants a 305 unless they are doing a stock engine swap.

If you really want to use your old 305, I'd put a stoker crank in it and bore it .060 over. Try to get 11 to 1 compression out if it unless its a track only car then go higher. Dart makes a nice Iron head that has a 49 cc chamber with 1.94/1.5 valves, this should help you get the 11 to 1 compression with flat top pistons, and make the engine a little more efficent with the smaller chamber. Put a roller cam in it, single plane intake and a 650 cfm carb on that you should have 325-375 horsepower for probably $ 2,000 if you do it yourself with exception of the machine work and block clearencing.

I'd personally get a 350 block and build that.

If you're interested and live close to me I have a used 350 short block for sale. It had a rod knock so it needs to get rebuilt. $ 150

If people can get a four banger into the single digets you can make a 305 fast. Anything can be done with the right amount of $$$

If people can get a four banger into the single digets you can make a 305 fast. Anything can be done with the right amount of $$$

Im willing to bet that its easier to get the 4 cylinder into the single digits than it is a 305. The biggest problem with the 305 is that its a long stroke small bore engine which limits the valve size and total airflow. Its wise just to sell it for what you can and get a 350.

If people can get a four banger into the single digets you can make a 305 fast. Anything can be done with the right amount of $$$

That was kinda my point.

Im willing to bet that its easier to get the 4 cylinder into the single digits than it is a 305.

I highly doubt that.

305 and 350 are same stroke (3.48")

1bdbrd is right, the small bore is only good for so much (great daily driver)

$ for $ you just won't get the results out of a 305
if you really had to you could use the 305's crank and rods and accessories to save some cash
get a 350 or 400 block (377 w/ stock bore and 3.48" stroke) and some pistons and good heads and cam of choice and be happy
-OR-
try to find some of world products '305 Torquer' heads (had em on my '86 305 TPI Z28) and a mild cam and a performer intake, small carb and good exhaust . . .make about 300 hp and have a great driver . . . .but not a great racer

it just doesn't seem worthwhile to try for 500+HP with the small bore motor
I'd rather have a 283 that'll rev to the moon if I was gonna go small bore motor

honestly, I'd just suck it up and build a fun driver and look for/build a bad motor in the meantime
FWIW the 305 H.O. was rated @ 190 in the f-body and monte SS
I forget what the LG4 was rated at, but it's lame (great mileage lol)

good luck :drive:

Back in the early 90s I built a 305 just to see what we could get and to my surprize we made 382 hp and 346 torque. What was done was a 305 block and a 350 crank which if I remember right makes it a 315 cu.in. Pistons were 10.1 flat tops with reliefs (hyper.) and used a Comp 280 cam. 1.6 fulcrum rockers. Heads were brand new untouched except springs Corvette 58ccs., and the intake was a Edelbrock RPM with there 650 carb. This engine had a killer idle, and I sold it to a guy that put it in a 71 Nova and that thing screamed. Nobody believed us that it was a 305 or should I say 315. If I'd do over i'd just stick to the larger cu.in. to gain even more but it was fun to do.

I do not think a streetable 500-600hp NA 305 is going to be easy to build. My bench-racer calculator says more displacement every time I think about it. I imagine it is possible, I just don't see how. Without some form of forced induction, you just cannot get enough air/fuel through that chamber. You will save a TON of cash building up a 350, though the 500hp - 600hp you mentioned are still not going to be cheap. A 400hp 350 wouldn't be too expensive, but the money starts to grow exponentially past that point.

You can take junk and make it fast, then all you have is fast junk, a 305 is junk when power is in mind, but a 335 stroker kit will liven one up if you were dead set.

Im lookin to get like min 500-600 hp. = $$$$$$$

Someone's 305 was that fast I'm sure. You’re not going to get there. The above recipe is about 350rwhp or a lot of suspension/weight work. Bet you can’t get there either but I like the set-up and 250rwhp is twice what you have now.

The heads can’t support high horse power! You will need a base with larger cubes or better heads and rpm for the hp level you said. I think you need to modify your hp level/goal. Your whole drivetrain, suspension and frame would need to be modified to handle that kind if power. IT WOULD BE CHEAPER TO BUY A MODDED LS1 THEN BUILD YOURS!

theres a local guy with a 3rd gen camaro who swears by 305s. he has one in his car and i think it goes high 12s.

I've seen a 9 second 305 once........and it had a turbo.

Back in the early 90s I built a 305 just to see what we could get and to my surprize we made 382 hp and 346 torque. What was done was a 305 block and a 350 crank which if I remember right makes it a 315 cu.in.


305 and 350 are same crank, 3.48" stroke, the difference is the bore

the 334 is made the same as a 383, by using the 3.75" stroke 400 crank and a slight overbore

I forget which mag did a 305 build that made near 400 and was very simple . They simply used Vortec heads with appropiate manifold , cam , rockers , and exhaust . All the parts could be switched to a 350 in the future . It was either Car Craft or Hot Rod . I want a 3rd gen but I'd go big atleast 400+ cubes , I really want a big block .

You can make just about anything fast. Depending on how deep your $$ pockets are and what you consider fast.

Still don't see a cheap or easy way to extract 500hp from a 305. Hell, it isn't all that cheap to get 500hp from a 350! For what he is asking for, he really needs to look at more displacement. The 305 is a great engine for what it was intended, but the cost of building it past 350-400hp is very prohibitive, and would most likely be unstreetable. He could buy a built 383 crate for a lot less money than he is looking at spending...

The Valves are a big limiter to what he wants to do, they are tiny! 1.94 intake just isn't going to flow enough (even with a perfect head) to support 500hp NA. IT is a shame to waste the shortblock he bought, I do understand that, but that is the price of hotrodding. Look at a lot of the small block crate motors available now. You don't see much in the 500hp range. THere are 425-450 hp ZZ4 combos out there that would move that F-bodya round sharply though.

I forget which mag did a 305 build that made near 400 and was very simple . They simply used Vortec heads with appropiate manifold , cam , rockers , and exhaust . All the parts could be switched to a 350 in the future . It was either Car Craft or Hot Rod . I want a 3rd gen but I'd go big atleast 400+ cubes , I really want a big block .
That was on an engine dyno with no accessories, it would make less with the belt drive and all the works.

Yeah I know but it made good power and was easy and cheap .

If you take enough time and spend enough sure you can make a 305 make power, if that's what you want to do.

305's are not the ideal choice but if you really want 500-600 hp out of it stroke to make a 331 or 335 or whatever it is with the 4 inch stroke, make sure it's forged. Build it for spray. Get the best heads, you can and a good cam for spray. Spray it with say a 300 shot.

I think you can get 600 that way.

3rd Gen's just beg for an LS1 instead of a 305...

I am going to build this shit out of it, but is 305ci just to little to get lots of power, or not a problem.

Click here, Preston Smith....! (http://www.cecoatings.com/images/other3rdgens/TurboCars/preston/Kinetic%20Engineering%20a%20305%20TPI.html)

Hey since no one is posting in my other thread i'll rectify this one. I am taking your guys advice.

I can buy a 400sb for 250 or a 454bb for 300 what should i buy. personally i want the big block but i can be persuaded to a high reving small block

I would go big block, they are cheap as small blocks and 500-600 hp can be done with mostly stock parts. I know the feeling of high reving sb, but there is nothing like tipping into the throttle of a BB and roasting the hides at a rolling 30 mph.

A 454, with the stock oval port heads, an intake, a carb, and 10.1 pistons, a lumpy cam, and a tourgue converter will yeild 400+rwhp. But your limitied to a 6500 redline.

Building a high reving SB will yeild the power you need, but above 7000, you will eat valve springs like toliet paper in a ladies room. Unless you buy revkits ($400 with no power added)

I have built plenty of nasty 305's and they ran like a raped ape, but 475hp is usally the most out of a 305, you have to remember 305 blocks are 2 bolt and the caps walk like a 3 legged dog.

Big Blocks can produce 600hp without breathing hard, a small block you have to wind it to the moon to get 600hp.

Just my opinion.

if you wanna spend some money on the 305 to make it go fast, it isnt worth it. Just go with a LSx engine, if thats too much for you(its good since its also light and compact) but if its too much, I woulndt go with a 305. I in fact have a 305 in my drontyard, painted orange. It has a cracked cylinder and can be resleeved. I would never use it in a car though... 305s all around arent good from what Ive seen. I dont know if its identical to a regula SBC, just teh block itself, but from what my understanding is... it isnt.

I really think a big block is what i want. I found a kit to make an all forged 540CI for 2k. I can have all machining done for free. What does that sound like? I can have a forged 540 for 2,300 incluiding cost of engine, parts, and labor(by me). And then i was thinking about buying a 6speed from an lt1 car and throwin in a 12 bolt, or a 9 inch with 4.10s

The end result is..."Well, if i did a 350...i would have 60-75 more HP....."


In all realitiy, there is no reason not to build a 383.

I really think a big block is what i want. I found a kit to make an all forged 540CI for 2k. I can have all machining done for free. What does that sound like? I can have a forged 540 for 2,300 incluiding cost of engine, parts, and labor(by me). And then i was thinking about buying a 6speed from an lt1 car and throwin in a 12 bolt, or a 9 inch with 4.10s


Depends if its good parts or knock off forged. You will need some nice heads for that CUI, no stockers if you ask me.



In the latest engine masters challenge they had a 302 ford that made 498hp and a 305 that made 398hp with what look slike a factory carb. Keep in mind they have rules on building those engines also.