Hey all!

I have a 1995 G30 that is getting terrible gas mileage and poor performance too. So I've decided that I need to work on the exhaust. I figured that I would put in a dual-exhaust system. Since I hate headers and the constant maintenance requirements, I'd like to install some exhaust manifolds from a high performance engine. Maybe a Corvette or Z28. Glancing in the engine compartment of the G30 it looks like there's plenty of room for some center output manifolds like from a 91 Vette. Can anybody suggest some manifolds that might do a good job? Or know if I can get away with some Vette manifolds? I'm not looking for 400rwhp, but I'd sure like to get the performance from the gasoline that I'm burning.

Thanks,

-KP

Center dump exhaust manifolds will not fit a late model Chevy van.
The down and out the back stock minifolds on our vans are really not to very restrictive.
a worn out closed up cat can effect you gad milage.
depending on the emission laws in your state.it can be illegal to remove your cats.
a good flowing dual exaust might give you 1 to 2 more MPG....maybe.
Make sure your fuel pump is in good working order and change out the fuel filter if it has allot of miles on it (over 70,000)

I just changed out my G25's fuel pump filter and sender unit it made a noticeable difference how the van performs.
I average 16.5 MPG's
TBI 350 95,000 miles

.......Wookee

16.5mpg! That would be a 50% increase! I can only dream...

That's great info. Thanks!

I was kinda planning on a dual exhaust/cat setup. But maybe that won't work with the ECM, because it doesn't currently have 4 o2 sensors? I could crawl under and look I suppose...

Thanks again.

-KP

You can combat that header hatred! BTDT! You need to buy good headers (I recommend Hookers) and quality header gaskets (Felpro premium header gaskets or I think another good brand is remco) also when installing the header bolts, use stainless bolts with lock tight on each bolt and wait for it to dry before running, and you shouldn't have to touch them once installed.

I'm gonna agree with Superbeast, if you get good headers and gaskets you won't have a problem.

I put a set of Doug Thorley headers in my '78 G10 about 12 years ago, they came with premium gaskets and I've never had a leak. Get the ceramic coating though, it makes good headers even better.

First off, how many miles does this tank have on it and what kinda van is it? A fully loaded convesion or what? And block huggers will work.

Center dump or rear dump block huggers? I would like to see a picture of them in place on a GM van. I tried using center dump block huggers on my 454 in my van and there's no way they would have worked.
I also agree with Ken. Get a good quality set of headers,gaskets and you won't have problems. Had a set of Doug Thorleys on my dad's 77 Suburban for almost 20 years and only had to replace one collector gasket. Brad

BLOCK HUGGERS WILL NOT FIT a late model GM/GMC van.......

The header if you go that way need to be made for a van.Pick up headers are too wide,and hang down too low.
Yes you will need to put the O2 sensors back for the ECM to operate correctly.....
My 89 GMC only has one O2 sensor
A good quality header with a 3/8's thick mounting flange to the head is also better.
One problem with running long tube headers on a Chevy is they can over heat the starter.They also make the starter harder to drop.

.......Wookee

I've got a lead on a set of HOOKER headers model # 2459. The owner says they're for a Chevy Van/motorhome. Can anyone verify the part # ?

I'll check today. I have hookers on my '83 and there is a little plate welded on the drivers side header with the part #.

I have a set of Hedman headers for your van. Check the classifieds. I would also recommend running a h-pipe. Nice boost for the low and mid-range.