Yes I do have the Thorley headers. I thought they would be fine on there... Thats a good point though. Thanks for bringing that up whippled!
What performance advantages are there to getting the large port vs. the small port heads? I figured the large port would do better with a much larger cam and the manifold upgrade. I would love to do a stroker and a blower eventually too, and I figured the large port would be much better suited for that.
Thanks guys!

-Rob Nap

 

i saw a new gmpp crate motor and the nhra drags in colombus sat. they are making a ht383e now. it is an emissions legal 383 that is a bolt-in for 96-99 trucks and no tuning is required.

 

Complete longblock with cam? Now they're on to something. There are plenty of those trucks in great shape with high miles out there that just need a powertrain upgrade. They did the same thing witht he 502 for the 454TBI. Sweet.
All 383 versions GM makes start with the same shortblock, I'm sure that will be no exception. Swapping in that shortblock was as simple as putting a stock 350 replacement would have been. Imagine starting with enough already built that all you need to bolt on it your intake manifold and accessories... That's a good deal.

 

I would think that if no tuning is required that it is a pretty tame motor. Still cool that they are doing that though. I bet it will have a very mild cam similar to the stock motor in our trucks now. If I was gonna spend the money to get a new motor I think I would want it to be pretty ballsy.

-Rob Nap

 

http://www.pacificp.com/forum/viewtopic.php?t=2670

Nice for someone with a worn out/blown Vortec 305 or 350.

peace
Hog

 

Here is a L31 for ya.

Ram Jet intake
E-tec 200's
Mild custom cam
S78 turbo
Custom headers and 4" down pipe
All stock bottom end

This will be the year to see what the stock L31 short block is made of!

 

I wish I had the dough to see what the stock block could handle... hopefully by the end of the summer I will be able to get the mods in this thread, that should keep me satisfied for a little while anyway.

-Rob Nap

 

Hey by the way... will the thorley headers definitely not fit the large port edelbrocks?

-Rob Nap

 

hellbents10, what really caps off your motor is that it's running A/C

I'd like to know more about your setup. I'm contemplating what to do with the tired stock Vortec 5.7 in my '99 Tahoe. I've read all the stroker threads I can find; I've read all the marine intake info; what I'm looking for is something "a little different"... and what you're doing fits the bill.

 

I love the set up that truck has. I wish I had basically the same exact one. Those valve covers look sweet too!
So does anyone know if it is a definite that the thorley headers will not fit the large port edelbrock heads? I just put on the thorley's on recently and i wouldnt really want to get new headers.
The other question I have is about the large port edelbrock heads vs. the small port heads. Which would be better for a 350 with with a cam and the ram jet manifold? I am looking to do more aggressive mods in the future, like the GMPP 383 that JamesB just got.

Sorry to dig up an old thread but im still curious.
Thanks!

-Rob