I was gonna rebuild my (otherwise bone stock vehicle) truck's fuel injected L31 into a 9.x:1 383 (eagle kit with 12cc or 18cc dish) with stock cam or 9.x:1 355 with LT4 cam and run it on mid grade gas. Stock manifolds and injection with dual exhaust. I've trolled thru a few dozen threads here on cams and compression. Now I'm totally confused. Where are my combinations wrong? 1999 full size van.

 

GM offers a 382 for your truck, using a 350 block, forged 3.800"-stroke crank, and dished pistons making 9.1:1 with L31 heads, and the RamJet350 cam, you can find it on Scoggin-Dickey's website, though you could duplicate it yourself for less than half the cost. My first question is why keep the exhaust manifolds? If you're wanting more go, start with headers, Edelbrock has some legal ones that fit great and will really help. Be sure to get a better-flowing muffler as well.

 

also, be sure to go with the 18cc pistons.

 

No headers available. Called them all. Very tight fit and unpopular application.

 

You'll be fine with the build - be certain to have the heads machined for adequate lift. Vortec heads are limited in the amount of room between the valve guide and the bottom of the retainer. The hot cam will require machine work. Aside from that, look into a good PROM and it should run pretty well.

 

Which build would you do then? given my parameters above would you go with stock everything with stroker crank OR 355 with LT4 and beehives?

 

Have you ever been under the dog house of your van. There is PLENTY of room on both sides of t he engine underneath. The frame is out MUCH wider than any of the trucks and the floor is below the header height. I have summit shortys on my 97 G1500.

 

I made a bunch of calls and was only going on what I was told by the call-up techs at pace, summit and jegs. I'm glad they are wrong! Summit shorties, eh? That would be awesome!

What part number did you use?

Were they much of a hassle to fit and get sealed? Did you keep the EGR? How close to the shielding and insulation do your's get?

You are the only person I've been able to find who's done headers on an express van.

It's only looks tight at the back of the exhaust manifold (where the egr pipe would connect if it where on both sides instead of just 1) it makes the downturn to the y-pipe. At that specific location I only have an inch or two between the manifold and the heat shield/insulation stuff that's stuck everywhere under there.