Small Block & Big Block Chevy Specific - Adding 1.6 Rockers

Currently building a new 355 for my boat.

4 bolt bored .030", align honed, decked .020"
Forged rotating assembly, Eagle 4340, I beams w ARP 2000, TRW L2304 pistons w .100 dome. Setup is balanced very well.

Comp XM276HR 224/230 .503/.510 112LSA 110ICL
Morel Retro Hyd Roller lifters
AFR 190cc heads 2.02I 1.60E milled 74cc puts SCR @ 10.0-1
Edelbrock Vic Jr or Performer RPM, I have both but undecided as to which to use.
Currently have Lunati 1.52 aluminum widebody roller rockers
Holley 750 4150 DP

My question is, do I stand to gain anything using 1.6 rockers instead of the 1.5's? I've heard it's better to run the 1.6's on the intake and leave 1.5's on the exhaust as the port on SBC's seem to respond better to duration changes rather than lift. Any merit in this?

I have a new set of Crane 1.6 Gold Race Widebody's on the shelf.
I've allready checked all clearances with no problems and the valvesprings are more than capable of the added lift. 7/16" AFR studs.

I would think they might help out some as the AFR heads flow very well in the .500-.550 lift areas.

Any help would be much appreciated.

i would say its ganna be slightly noticable but not much its ganna change your lift to around 540 lift instead of 503 but if i had some layin around.. actualy i wouldnt have them layin around they would be on the motor if they were mine :judge:

before doing that be sure to check the p to v!!!!! you need .045 clearance MINIMUM with cast or steel rods .060 for aluminum rods. after you go to 1.6's your lobe lift is now about .335/.340 therefore if you go to 1.6 you will have .536/ .544 lift. never over look the piston to valve clearance when making this change

before doing that be sure to check the p to v!!!!! you need .045 clearance MINIMUM with cast or steel rods .060 for aluminum rods. after you go to 1.6's your lobe lift is now about .335/.340 therefore if you go to 1.6 you will have .536/ .544 lift. never over look the piston to valve clearance when making this change


Thanks. I've allready checked PTV and had well over .100 clearance on both intake and exhaust. From my researching it shows the 1.6's will be a tad harder on the valvetrain and springs but I bought the best out there and should be worth it.

I'd look into the comp cams pro magnum 1.52 They'll free up a lil horsepower from less friction over stamped rockers, but you really won't have to worry about too much lift. These are what i'm gonna get for my 82'.

honestly I dont think you would feel any diffrence, but im sure on a dyno you might see a few poneys added

The 1.6 rockers with help your mid to high rpm power. You are correct about the exhaust responding better to duration (for the most part) rather than lift. I would try the 1.6's all around the motor first due to the "quick lift design" of the Crane rocker arms. Then try just the 1.52's on the exhaust side. I would try to use the boat for a little while first so that when you make your changes it will be easier to tell if there were any gains or losses between changes.