Small Block & Big Block Chevy Specific - BBC Tall vs Short




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jh_shady01
10-04-2009, 01:02 PM
Why does nobody want to build a tall deck? I have both a 427 and a 454 tall deck. The 427 is 4 bolt main and forged steel crank. I havent started to build either yet because I dont know why these are undesireable?


89importeater
10-04-2009, 01:16 PM
well i dont know about with 4th gen but in 3rd gens the taller deck causes fitment issues with headers and such.

mrdragster1970
10-04-2009, 01:21 PM
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The 427 TD truck block is highly desired in my circle of racers.
The added rod makes a much better combination in our opinions.
A lot of guys don't want to spend the money on headers or intakes.
I didn't care. I have 2 intakes, one of each, and I have custom headers,
that were made to fit a 9.8 & 10.2 deck.
I understand why, but the better ratio is worth the extra effort.
If you're starting from scratch, I say use the truck block.
Good luck.

.


twinturbo496
10-04-2009, 01:36 PM
454 tall deck?

kenSS
10-04-2009, 06:14 PM
i have a 427 tall deck in my chevelle. headers bolted up with a problem. Rod ratio is the biggest reason to run them. Run it. Stock they had 3 compression rings then the oil ring on these truck motors.

ZONES89RS
10-04-2009, 06:58 PM
Well, as stated above, the third gen guys need the room. Not to mention a street motor doesnt need the ins and outs of a pure drag motor. So for simplicity a short deck is better. But if you dont care, why stop with a 427 or 454 TC? Go ahead and plunge to a 572, 598 or 632 if you are going to go that route:)

mrdragster1970
10-04-2009, 08:05 PM
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Ok, I guess I assumed a couple of facts when stating my 2 cents.
If it's not a drag engine making decent power, then there is no advantages.
A street engine doesn't run as hard & the better ratio is no biggie.
If you're trying to squeeze it into a tight modern car, probably more hassle than it's worth.
I assumed new rods, pistons & crank. If this is a stock rebuild, no advantage.
I pictured an older car with a frame, not a modern F-body with the towers in the way.
Since you already own them, I still say use one, you aren't losing power or reliability.

.

twinturbo496
10-05-2009, 03:06 PM
My 2 cents: Look at the available aftermarket rods, you can mill a little off of a 427 truck block & then use stock pin height 454 pistons (cheap) and use a 4.25 stroke crank to build a fairly cheap 496 with good rod ratio. Using common 454 pistons saves a bunch over getting custom pistons to build a short deck 496. Ebay has plenty of used intakes for tall deck big blocks for less than a new short deck manifold.

But if I had to do it all over again I would just buy a 572 tall deck with a credit card and be happy with a better rear seal, oil pan gasket, main bearing lube.........

Mine has 454 blower pistons that has taken 6800 without any issues.

JUICED96Z
10-05-2009, 10:01 PM
For the average street guy there is no need for a tall deck but if you find one in the back of some barn chances are you will be able to make some money on it.

Any good condition BBC block is worth money. I sold my 71 ish 2 bolt main 454 block that was 60 over and needed tanked and honed for $75 picked up... in a better economy I am sure it would have pulled more. The guy told me they are hard to find now because when scrap prices were high everyone was selling their blocks to the scrap yards... he drove like an hour on the highway in a 454 Chevy truck with a manual tranny and 4.10 gears to get it haha.

jh_shady01
10-06-2009, 12:14 AM
I was planning on building the 454 and stroking it to a 496. It will be going in my short bed, header fitment shouldnt be an issue. I plan on balancing everything. I want around 600hp/600tq. Kinda hoping to sell the 427 4 bolt, steel crank, to pay the machine shop for the 454.

mrdragster1970
10-06-2009, 12:21 AM
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The pistons are the same for a 9.8 & 10.2 plenty of choices off the shelf.
The difference is in the rod. We've built plenty of TD engines and never needed custom anything.

.

JUICED96Z
10-06-2009, 05:40 PM
I was planning on building the 454 and stroking it to a 496. It will be going in my short bed, header fitment shouldnt be an issue. I plan on balancing everything. I want around 600hp/600tq. Kinda hoping to sell the 427 4 bolt, steel crank, to pay the machine shop for the 454.

454 blocks are still fairly cheap, some machine shops charge an arm and a leg for a block that is machined but often you can get a good block cheap, have them check it out and save some money.

My old 468 BBC I am sure was making about 600hp N/A. There are some old aluminum BBC heads you can get cheap (like $1,200 or so for a set) that would support that. I have the Holley strip dominator intake still off the last motor (rectangular port) that is for sale.

Factory 454 rods with ARP bolts are good to like 800hp, you don't need a 4 bolt main, my motor had factory rods and ros bolts with a 2 bolt main and factory main bolts and it held a 300 shot no problem. For 600hp you don't need to go forged or anything to fancy.

I also had a factory crank and forged off the shelf TRW pistons... no problems at all.

Factory BBC stuff will handle a lot more power then people think.

You might thow some off the shelf forged pistons in it thow so that if you ever wanted to spray it the motor would handle it... nothing fancy.