K i have my 76 monte that has no insurance as of now so havnt drove it enough to get a good estimate of the gas milage but im trying to get a good idea of wat it is everywhere and nobody knows for older cars but even if they did my problem is it has an engine out of an 86 caprice classic cop car the ho 305 with th 350 anybody gotta good guess of mpgs . thanx

 

My Guess ~> 20 MPG
It's really very difficult to guess a estimate on your Monte since it has a difference engine & mod's

It also depend on the gears ratio in the rear ? the condition & tune of the engine that's in it now ? How it is being driven ? Aggressive or only @ posted speed limits ?
Does it have a A/C ? (if so, it will decrease MPG's)...
How many miles on Monte & on Caprice Engine ?

It will be interesting to see what other member's post...
Hope that you can get insurance & get your Monte on the Road & go for a trip & find out...Good Luck

 

Like space said, it is hard to tell specifically with out knowing more. My guess would be 15-19 mpg.

 

my dads camaro gets less than 15 mpg with the 305 in it. so my guess would be under 15 since the monte is alot bigger

 

k thanks all that i'm certain for now is than the engine has 74000 on it and body about 170000 everything but the engine is stock from the factory and the 305 has no mods either just out of another car lol

 

Since the 305 HO was used in the 80s monte SS then I would say your MPG should be similar to the MPG of the SS. Since you have no overdrive, your highway MPG should be less but city MPG should be similar.