cyclops2

I want to build a 383. I have an L98 block. The tranny is going to be a T56 with 3.73 gears. My plans are to run nitrous (150 shot), and race a lot. I already have the H.S.R. I need help picking out a cam, pistons, rods and a crank. I also have a set of aluminum heads from a corvette, but I don't think they're going to flow enough. I was looking at the AFR 195s. Can you guys give me some input and help me out?? Thanks for your help.

JakeJr

Since you're going to spray I'd definitely go with a forged crank and not a cast one. In fact, all the rotating and reciprocating parts should be forged - crank, rods and pistons.

Shoot rod connecting rods rated for at least 500 HP. Your engine may never be called on to make that much, but the margin of safety will let you sleep better at night.

I'd also have Oliver four bolt caps added to the center three mains on the block and use studs on the front and rear main cap. This'll call for align boreing/honeing the block.

From experience, once you spray with a 150 shot you'll begin to wonder how a bigger shot will feel. That's when a stout bottom end pays for itself.

Build it stronger NOW and you won't be re-building it later after something in the bottom end lets go..

There are lots of excellent companies out there who can provide you with a matched setup - crank, rods and pistons.

For me, JE pistons are top of the line. I like Manley valves; CompCams camshafts, springs and rocker arms. Clevite bearings; Moroso blue-printed oil pumps; Speed Pro single moly file-fit rings with their standard tension SS50U oil ring package (+.005)

I'd go internally balanced too.

Just my thoughts.

Jake

TKOPerformance

Shop on eBay for Eagle or CAT stuff. It is always way cheaper than buying it through a dealer, and it is brand new in the box.

Get a 4340 forged crank with .125" journal fillets. Get 4340 H-beam rods with ARP capscrews (5.7 or 6"). Get forged pistons that use standard street style rings (JE, Probe, Mahle, ect). Go for about 10.5:1 compression as advertised. In actuality this will yield about 9.8:1 because of the deck height on a typical small block Chevy. Use head studs. 4 bolt caps with splayed out bolts too (Oliver or Miloden). Figure on spending about $1,000 on machine work to do it right.

The AFR heads are the way to go. They are awesome! Since you're running juice and a factory EFI you will want to stay a little conservative with the cam. I'd get an LPE or TPIS middle of the chart hydraulic roller. Also, run roller rockers, but stick to 1.5s, because the valvetrain will last longer, and if you size the cam properly you don't need additional lift/duration. Pay particular attention to your valvetrain geometry.

The HSR is a good choice.

Make sure you ignition is up to the task. I'd recommend a DUI setup with their wires.

This setup should be good for up to 700HP, which will give you a good safety margin, or the confidence to increase the N20 shot in the future. This engine should make about 375-400 HP all by itself. The spray will push you into the 525-550 range, or better, because nitrous kits are notoriously underrated, particularly when you start to lean them out from the factory jetting, which tends to be overly rich for safety.

cyclops2

Do you think that it would be better if I ran a 355 or a 383?

TKOPerformance

To build a motor the way we've discussed you might as well go with the 383. It's going to cost the same, and more cubes mean more torque. Plus, a bigger engine can run a bigger cam and bigger heads and still be streetable, but smaller engines become much more tempermental as the power level climbs.

JakeJr

I agree.

Jake