I eventually want to pull my 305 tpi but i was wondering if i get a 350 tpi and rebuilt it. Hypotheticlly speaking is this thing gonna drink gas? Is it possible to have a 350 or 305 doing like oh 13.5 in the 1/2 and still get 18 miles to the gallon city ?

 

I think you could get the numbers you want with a 350, but if you got your AC running it might be a different story. It depends on a lot of things, even the weather is a factor, the hotter it is, the less mileage you get. Also the kind of traffic you deal with etc. All in all there is not much of a diff. in mileage between the two engines.

 

If there aint much difference ill defintly do it. If i can get the added power without sacrificing too much on fuel economy. Im just afraid of modding out and gettign the 11 mpg i hear so much about.

 

I got 11mpg in my 305 on good weeks. Of course it was supercharged. I am also planning on swapping a 305 with a rebuilt 350, but I haven't decided on the manufacturer. I dont want to blow the bank on an engine just so it can say GM on the invoice.

 

Man, I get 10 mpg with the '57, with no overdrive, no lockup converter, INCLUDING the 1320 runs!

Anybody who only gets 11 mpg in regular driving is doing something SERiously wrong.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet (Holley 3310 on the way), GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

Wait a minute, you said 13.5 in the 1/2:

Is that seconds & miles, or minutes & blocks?
If the former, it WILL drink gas...