383 build
With the 3.9 bore the 346 and 4 inch stroke 383 will make very similar peak hp. However, the 383 will make it at lower rpm and the 383 will usually make about 25 to 35 more foot pounds of torque.
LS1/LS6 383 stroker motors are more about torque under the curve than peak hp.
If big peak hp numbers are important toss the LS1 block and upgrade to a LS2 with 4 inch bore or LS3 with 4.06 bore.
A good set of ported heads & cam will benefit more for the dollar cost than a 4 stroker crank.
Expect to spend $2000 to $2400 on a stroker crank, rods, & piston rotating assembly plus usually some extra work clearancing the block and balacing the assembly. Often about $500 for the typical shop to do for you. So $2500 to $2800 to do stroker crank. Plus windage tray & custom crank scraper.
Excellent heads & cam set ups can be had for less.
Personally, I like the driveability of the 383 LS1 stroker with heads & cam in my RS with the extra torque way better than heads & cam LS1 in my TA. Under 3000 rpm in the daily drive range the RS is way more fun to drive. Both cars are six speeds with 4.10's. The extra 35 to 40ish foot pounds of torque were worth the cost.
Comp Cams Tri-Power Xtreme™, TPX 254HR-16 Part number 54-530-11?
If that's the cam in question is like a 202/212 at .050 with .507ish lift - way too small for a 346 in my opinion, never mind for a 383 in my opinion unless its being used for towing. I dont think this cam will get you near 500 crank/fly wheel hp without a power adder.
I think Lunati makes a nice crank based on what I've read but i haven't had a build done with their products. Both Callies Compstar cranks (one in the RS and one in the vette) were spot on when checked. They didn't require a lot of extra work.
It's my understanding that Molnar LS cranks and rods usually are high quality, very close to the mark and don't require as much machine work normally. I'm reseaching Molnar and K1 next time around with an engine project.





