So im planning on a 3.1 to 350 swap, the thing is right now im getting around 20 ish MPG, i would like to keep it in that range, what would i need?

 

BTW i want a manual for the whole swap

 

My 350 gets about 17mpg as listed below, whether I'm having fun around town or driving highway for 8 hours. I would have thought your V6 would have gotten closer to 30mpg, my old 305 TBI got 30 highway.

 

probably its the shitty gas we have down here, or that the closest thing to a freeway here is like 8 miles long hahahahah, but yeah im getting around 22-25 MPG

 

Well gas mileage depends on how the motor is put together. Although if you went with a TPI set up TPI motors got about 20 MPGs on average from the factory. Granted once its modded everything changes not neccessarily for the worse but like i said its all in how you build it.

 

last night i was reading about small blocks and found info on a 305 that was budget built and put our pretty decent numbers, something like 300 hp and 330 ft/lbs, getting 20ish mpg and it was running on a Q-jet carb

 

the two things that will affect the milage the most werent mentioned yet. What trans and what rear gear are you going to run. my 305 tpi got 30 hwy at 70 mph turning 2k rpm with the 2.73 rear and a 700r4, with the new 342 rear i get 24mpg at 70 mph turning about 2700 rpm. if you go with a t56 trans and keep your 3.08 gears ( im assuming that what you have) your milage should be upper 20's

 

im plannig on going manual, im hoping to get a t56 but if i cant find one ill go with a t5.

 

You can get reasonable mileage with a 350. Using a feedback induction system is the best way to maximize that. I get 23 mpg highway, 17 mpg commuting with computer q-jet, TH700R-4 overdrive tranny, 3.23 gears. See sig for the rest of the details.

 

id rather stay carbed, getting some sort of engine managment here in mexico is kind a hard.

 

I get about 26mpg on my LB9 with mods. I have the 700R4 with 2.73 gears. At 2k rpms, I'm at 80mph...