96 express conversion van 383 build (header info needed)

[chucksrt]

I am finishing up my build for my Hi top conversion van. I built everything new rather than use the original engine to build. The prep work for the block alone would have been more expensive then doing what I did and get a 4 bolt main block already prep'd for the stroker crank and machined and ready to go. I got a block from summit and a Scat 383 rotating assy. with forged pistons -18 dish., milodon 7qt pan and pickup, comp cams roller cam Duration at 050 inch Lift 206 int./210 exh.Advertised Intake Duration 262
Advertised Exhaust Duration 264
Advertised Duration 262 int./264 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.450 in
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.480 in.
Valve Lift with Factory Rocker Arm Ratio 0.450 int./0.480 exh.
Lobe Separation (degrees) 112
Grind Number CS 262H-R12
comp cams roller lifters, Edelbrock 60979 Aluminum heads, 1.5 roller rockers, custom length pushrods, newer style spider assy. and summit distributor along with some stuff i know i'm forgetting! I am looking for headers but would prefer long tube ones but I only can find one company that makes them (Doug Thorley) and they are over $700. does anyone know of any other headers for this van or do you know if shorty headers will do the job? The manifold on the driver side has the provision for the egr tube, can the egr be bypassed without setting a check engine light? Once I figure out what headers to use, I plan on running 2.5" pipes to two cats into a dynomax dual in/out x pipe muffler #17553 then into dual 2.5" in/single 3" out gibson muffler to 3"tail pipe. Want it to look stock and not be too loud but still be free flowing enough to make some power. Once it's running I will have it dyno'd then send the results with the computer to PCMforless to do a custom tune. I hoper to make around 350hp with around 380tq? still has the factory 3.42 rear and stock 460le trans. for now. Trying to retain the best mpg I can while bumping performance!

[chucksrt]

Going to order the long tube headers from Doug Thorley. They include all of the provisions for egr and o2 sensors and come with gaskets and y pipes. unable to post a pic.:(

[mgrotel]

I would go more aggressive on the cam duration, I had a 210/214 in my 383 and it wasn't enough cam, fell on it's face in the upper rpm

[chucksrt]

I would go more aggressive on the cam duration, I had a 210/214 in my 383 and it wasn't enough cam, fell on it's face in the upper rpm

What rpm did you feel it start to drop off? This is being built with keeping it as mpg friendly as I can! When it's all done I am going to get it dyno'd and send the info along with the specs to PCMforless to reflash the computer. I had originally picked out a bigger cam but I was told that it might not be the best idea with a van as heavy as mine.

[mgrotel]

4500ish

[chucksrt]

This cam says it's good till 5k? I should have the headers by the end of next week and the computer just went out to PCMforless for a base tune. once I get the van running I will have it dyno'd and maybe have it retuned depending on the results. I am thinking about getting the throttle body bored out too. I don't have room to add the v max spacer so I am limited. I will mark the intake gasket to see the shape of the ports on the head and match it to the lower intake ports and clean up any over lap for nice free flow! I am pumped to be this close!!!

[chucksrt]

I've gotten everything together, headers on, trans built to take a serious pounding!! Just put the trans in today but I'm waiting for my new radiator to come in so I can hook the cooler lines up and install a stacked plate cooler in line too. I have had a bunch of set backs but I should be nearing the finish line now??! I had 3 birds get in my van through the dog house that I left off while I work on it so now I have some poop to clean up!! This better run it's ass off for all of the crap it's put me through!!!

[chucksrt]

Got the exhaust together just to get it road worthy. Now that I can hear the engine it sounds like s#%t!!!! The 2 year old gas won't let me give it more than a hair of gas, any more than that and it just sounds very pingy!! The drive belt tensioner or pulley are going bad, a tap from the engine, may be the header gasket? or the pulley, almost sounds like a lifter tick but it's not constant. I have my work cut out for me!!! I just filled it with 14 gal. of 93 octane still sounds bad. I will remove the drive belt tomorrow to eliminate any acc. noise.

[Zimsilverado]

The hp numbers are based on a 350. The bigger cubes will knock the peak down 300 - 500 rpm. Also the cam will be milder in a larger cube motor.

[chucksrt]

starting to think it might be a sticking lifter?

[SUBURBIAN]

You're going to have to provide more details to troubleshoot your noisy engine over the interwebz. Oh, and for the record, head flow limitations will trump cam spec limitations for the "nose over" every time.

[speedracer326]

It's quite possible it's going to run like total ass until you get a tune.

[chucksrt]

It's quite possible it's going to run like total ass until you get a tune.

I have a tune for this already! I just have to drive the 2 year old gas out of it so I can get a full tank of 93 octane in there and drive it.

[Mobilesport]

Do you have a part # for them headers ?

[chucksrt]

Thy-343y-c They are not listed on their site and you can only get them directly through them (can't get them via summit or jegs) I can forward you an email that they sent me with a number of pics if you like PM me your email address and I'll send you what I have. Also the kit is a direct fit for the 2500 series van with the 4l80e trans not our 1500 series with the 4l60e so the front pipes they send with the kit need to be cut short on the pass side.