I`m looking at putting vortec heads and tbi manifold onto my `88. what type of gas mileage am i looking at? For now I`m just replacing the heads with vortecs milled down to 58 cc and installing the GM tbi/vortec manifold? Are there any better options for the intake manifold?

 

I'd almost think It wouldn't make a really big difference in MPG, since the cam is still the same. Maybe loose a little bit but I don't think it'll be that bad.

 

So if I was to change out the cam, it would lower the mpg? What would be a good cam to put in.

 

Hey Pandora,
if I were you I would do exhaust and headers first, then heads and manifold. Or at least do heads, manifold and exhaust/headers at the same time. Without a good flowing exhaust I think the gains of swapping in heads and manifold will only be half of that what you would get with it.
But anyway, that's just me.
If you are looking for a cam:
I am just going to do a cam swap and will put a Crane 2031 Powermax in.
You can find information about it here:

http://www.cranecams.com/master/apps/chevy37.htm

I will also change my heads, manifold and timing chain. The rest of the mods I have already done is in my sig.
If you like some food for thought, look at this thread:


https://www.thirdgen.org/techbb2/sho...threadid=91636


It was started by me some weeks ago, concerning three cams which I considered to be suitable for my LO3.
Look at what Nitroburn says about mileage.
I hope this helps.

Later,

Andreas

 

with my old set up i was still seeing about 22-24mpg on teh highway. that was with the fuel pressure set high for racing and no lock up convertor. i woudl say you can still see at least 25-26 mpg on the highway if you car is tuned right.

later
tim

 

Tim, what was your old setup? Is it the one on your page? What kind of cam did you put in? I did't find anything about your cam on your page.

Later,

Andreas