I have a GMC 270 motor. Does ANYBODY know how to improve gas mileage? Is there an aftermarket throttle body?

Well, maybe you would get better info at a GMC site.

Improve it from what figure? Is the engine in a truck or car?
I would doubt if it is capable of doing better than 15 MPG.

Not the exact same question - but - from the hotrodders forum...

Hi all, can anybody out there suggest how to increase the power and RPM on a 270 in-line 6 cylinder GMC engine, I have heard about fitting a 302 head but then this will require new pistons as the 270 ones are domed what sort of pistons would be needed to give a reasonable compression ratio. For increasing the RPM does anything need to be done to the crank or rods ? Is the 302 head ok for more RPM ?

All the "answers" and advice suggested getting ahold of Patrick's in AZ.

Probably good advice....

Bill.

or go to the Stovebolt or Inliners Int. web site