i have an 01 silverado rc 2wd, i am building a 383 out of a 5.3l block and will be putting my vortech supercharger back on it, what heads/ cam combo do you guys think and what other mods would ya'll suggest? i want to keep it street/strip. i have 3.73 gears and gibson shorties but am thinking about long tubes! just thought i would get ya'lls input. pls help!!!!!!!

 

I don't think you're going to get to 383ci from a 325ci block.

 

5.3L block can go out to 3.9" and with a 4" crank that gets you a 382 so close enough.

 

Hmm. Ok, but wouldn't the cylinder walls be very very thin? IMO if hes going to get a 4" crank and do machine work anyway (on the 5.3) why not buy a 6l block and go for the 408ci?

Either way, longtubes are a must with that much motor and FI. The cam will depend on your goals.
Heads....call Richard (Sponsor) at WCCH-------------------------------------------------------------------------------->
and ask him. He will give you the professional opinion.

 

I think the cylinder walls are the same as a stock LS1 at that point. IIRC, the liner is the same as a LS1 just the bore is smaller to start with.

I agree with the rest of your post too.

 

I say go straight to a 408 stroker

 

He has his mind made up, let him build the 383 the way he wants it.

Going FI i would use the 6.0 317 heads, larger valves and ports, and a larger combustion chamber, it will lower compression some to help with the supercharger.

camshaft, well for me i would use the 02 LS6 or the G2-3, both cams work in the mid to upper rpm range where the vortec will be making most of the boost pressure above
3000 rpms and both cams are proven to work very well on a blown set up.

 

what flow numbers would be better if i decide to go with the 5.3 heads?

305 cfm intake, 223 cfm exhaust

or

293 cfm intake, 223 cfm exhaust

 

LoL. Most companies that sell aftermarket LS-based blocks and short blocks for 383's use the 5.3 block. Thought I might add my cents since I've built a few in the shop.

 

HEHE i work for GM and we have done close to 383... so trust me it works... and if its what he wants to do then i say right on....

6.0 heads would be your best bet bty unless you go WCCH.... with what you have invested it sounds like your pretty serious... i would say spens a lil extra money and get some headas done that will work for your setup, and not just something that will work