Nov. 05

Hi all,

I've just purchased a 1988 GMC Jimmy with a Chevy 350 V8 motor. I need such a large vehicle as my hobbies require the towing of large trailers.

Therefore I need to get the very best mile-per-gallon figure I can.

Currently with a stock engine, K&N air filter and 3" bore exhaust i'm getting 15 mpg per US gallon (not towing).

I'm currently sourcing a rebuilt set of heads specifically to deck and groove them per the thinking and specifications of Mr Singh.

I also intend to install a shift kit in the transmission to hold the vehicle in 4th gear (again not towing)

Other ideas are water injection and a Helix throttle body spacer (which I have but have not yet fitted).

I'll keep you posted on the progress.

If anyone else is working on a similar path with a Chevy 350 I'd be pleased to hear fronm you.

Regards,

Trevor Heath
Port Orchard, Washington USA

March '06

I finished up the project on Saturday.

The motor started first try and while the ignition timing may still be a little off, the motor is idling smoother and, at a higher RPM than before the grooving.

In my case the motor had 176,000 miles on it and had never been apart before.

We replaced the valve springs and valve seals in addition to a "valve job" in addition to milling the head .040" and cutting the grooves.

While I still have the use of another vehcle, I decided to service the transmission and add a transmission cooler as well so it will be another week before I start putting miles on the Jimmy.

I agree with you though that I too find this vehcle very useful except for the fuel mileage, my best was 14.8 mpg per USG. For the record the vehicle was getting 14.8 MPG (US GALLON) in stock trim except for a K&N air filter and a 3" exhaust from the cat to the tail pipe.

I'm hoping to get 20 mpg per USG.



TH

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