Skip Fix

But do the manifolds have a big enough outlet? They look kind of dinky.

Jersey Village as in north Houston?

Keith

My father and I swapped in a HT383E into his old 99 CCSB Chevy.

We had some issues with issues with it, although they were cause by the old poppet injectors and not the engine. They were replaced by the dealer and all was well after that.

Unloaded, the truck got 15mpg and had quite a bit of oomph down low. A lot more then the old 350. Dad used it to tow roughly 6000lbs, 3600 miles and averaged 9mpg I recall.

Eventually we got tired of being passed by Dmaxes hauling a load and got one of 'em. I think it'd be a great engine if it could breathe up high.

YenkoST

iTrader: (11)

The 3/4 ton trucks have head pipes that are 2.75" for the BBC. But, I would recommend 2.5" max for a SBC.

You'll have to go with headers for the collector size you want.

hog

The 2nd page of this thread has pics of the dual 1 7/8" 1/2 ton headpipes sitting next to the dual 2 3/4" headpipes from a 3/4 ton.
The stock pipes crimp down badly in the 90º bends.
http://www.pacificp.com/forum/viewto...r=asc&start=20the 1/2 ton and 3/4 manifolds are the same. Go longtubes for full effect.


HT383 will run just fine on a stock tune, however you will be leaving lots of performance on the table. The part throttle fueling will adjust, the WOT tuning will not adjust at all.
Doing a full exhaust and PCM tune on my truck felt like I dropped a 383 under the hood, not exageratting. These stock exhausts suck.

Tunercat is a good program with good support. It will tune some things things that EFI/HP will not. Many pros use TC2 as it allows for custom VDF's. CAN support is in teh works.

peace
Hog

bai78

sub'd

Skip Fix

Most manifolds I've seen have a set pipe and flange for the outlet ie a 1 7/8 exit is not going to seal on a larger pipe or even fit in the flanges. So the 3/4 ton would have to have a different manifold, Seems like a headpipe/cat system would be worthwhile to market-even if it fit a shorty header.

YenkoST

iTrader: (11)

Magnaflow makes a system with cats that's 2.5" I believe.

The actually manifold I believe it 2 1/4" on the inside of the manifold but it necks down with the gaskets, etc. But, the manifold it really restrictive design so shorty headers will help but long tubes would be the way to go with a custom system and cats. Probably come out cheaper that way.

hog

The 1/2 ton and 3/4 ton manifolds are teh same thing. If you look at the picture I posted, you can see that the smaller 1 7.8" headpipes have a larger bevel crimp at the end to fit onto the manifold, while the 3/4 ton headpipe has less of a crimp that mates to the manifold.

peace
Hog