Just took a ringland on my LT1 and I am in the process of looking for info for a 383. This is what I have so far....
The shortblock is a fully forged 383 5.7" rods ,-31cc dished JE Forged Pistons.
I already have LT4 stock castings with the stock RR's, Springs and Push rods. Also an LT4 intake.
I have a P600B with 3 core intercooler and 8 lb pulley.
Most of my budget has gone into the shortblock so I was just going to bolt on the stock LT4 heads and intake with the blower. I figured I should spend the money on a good foundation first (shortblock) and get the car running again by bolting on what I have and then later on porting the heads and getting a larger blower.
My questions are: will this setup be ok to make some nice power until I can afford to upgrade the top end?
How much power can be had from this setup putting in a cam with the following specs...214/224 at 0.050 0.565/0.605 lift 114 lobe seperation.
and what would the compression be for the JE pistons and 54.4 CC combustion chambers from the stock LT4 Heads?
Thanks in advance.

 

With pistons with CH of 1.425, -31 CC, 5.7" rods, 3.75 stroke, .0395" felpro gaskets, and 9.025 deck height i calculated the static compression to 8.92:1.

Hope it works out.

-Stu

 

Thanks Stu I guess that would be good enough. I was hoping to fall between 8.5 and 9. How does dynamic compression fall into the equation?

 

the biggest concern i see with your setup is in the valve train. if your using the LT4 RR's they are 3/8" stud self aligning and i would not trust them with lifts as tall as the specs of your cam. also, with the spring pressures your going to be running i would seriously invest in the 7/16" rocker studs for stability and to reduce valvetrain movement where you don't want it. not dsaying you need a shaft mount setup, but guide plates and ARP 7/16" studs witht he larger non self aligning rockers would be the minimum for reliablity.

hope this helps!

Chris

 

Dynamic compression depends on the ammount of boost run and how you set up the cam. The intake duration is rather short, so the cam wouldnt lower the dynamic compression much at all unless you degree the cam back to close the intake valve later (talk to your engine builder to see what they suggest).

I wouldnt go with SA rocker arms over .550 lift, especially with Crane Race Gold 3/8's. Like NC-LT1 suggested, I would go with Comp Pro Magnum Non-Self Aligning rockers on a 7/16 stud (get APR studs). You will need hardened pushrods and guideplates (i suggest GMPP #14011051). With that kind of lift, you will need to make sure your springs can handle the lift, or you're gonna get spring bind and some bent pushrods (if only that). With the stronger springs, might need to upgrade to the Comp-R lifters too.


Good luck,
-Stu