I was thinking since I need to rebuild my engine...again Should I rebuild my LG4 or go with a 350???? Between a stock 305 and a stock 350....is there major gas milage differences??? I dont really wanta put in a 350 if its gonna give around 10 Mile to a gallon. I want some power and some good gas mileage too. My LG4 gets me only about 160HP and 13 miles to a gallon with a TH350 transmission. Probibly puting in a T-5 would help with the milage too. Thanks guys.

 

OMG 13 mpg, even my l98 gets better mileage then that. i mean i think the mileage is a bit low even for a 350 at 18mpg average half city half freeway driving, but i have some suspisions where the mileage is going.

a decent 350 can still turn in over 20 mpg if it is tuned and running right. i keep poping a lean at cruise code so i know the motor is going over rich to compensate.

 

It's all in how the motor is built and driven. One guy get 30mpg with his 350. TPI will best for gas.
I get 17-18 and that's with a Non-lockup converter.

 

Since your Canadian, you will understand my metric numbers. Last summer I took a trip from Kamloops to Calgary (610 Kms) and I only used 49.5 Litres of gas. This is driving through the Rocky Mountains and passing lots of slow moving RVs.

I have invoked Highway Mode in my eprom though.

 

A 350 will get comparible fuel economy to a 305 under normal conditions. If you want good economy with a 350 use a replacement truck cam like the melling MTC-1. Torque cams provide great fuel econmomy, especially in cars. My firebird in my sig gets 18mpg city without driving like a granny.
SSC

 

Whats that?

 

Id go with the 350, I have an edelbrock 750 carb and performer intake and I get 22 mpg, keep in mind I have a 3 speed and 2.73's.