engine swap?

[spidereyes455]

I did this swap back in the late 90's. Not hard to do all the original brackets from the 400 will work fine in the cutlass the one thing you will need to change is the pressure hose fitting on the back of the power steering pump with a newer one that uses the metric O-ring line. I also just checked napa's website and the mounts are the same for a G body with a 301 and a 75 to 81 Firebird with a pontiac engine.

 

[78 salon]

I did this swap back in the late 90's. Not hard to do all the original brackets from the 400 will work fine in the cutlass the one thing you will need to change is the pressure hose fitting on the back of the power steering pump with a newer one that uses the metric O-ring line. I also just checked napa's website and the mounts are the same for a G body with a 301 and a 75 to 81 Firebird with a pontiac engine.

Napa sells motor mounts, not the frame pads.

 

[spidereyes455]

They sell the frame pads because thats where the rubber is . they look almost identical to a small block chevy mount, but they are different. I bought a set when I did my swap, and still have them and the engine brackets . the point is the firebird mounts would be the same.

 

[jospooner83cutlass]

Dose anyone have any idea about how gas mileage is with a 400?

 

[DoubleV]

Dose anyone have any idea about how gas mileage is with a 400?

Depends on too many different things to say. An old school big inch motor is never going to be great on gas but depending on build and tune can still be pretty good as long as you keep your foot out of it.

 

[dogsht]

Transmission, stall converter, rear gear, carberator, & camshaft can all be big factors in mpg. My 509 that ran 12.5
@110 with 3.42 gears pulled off 17 mpg HWY. It had 200-4r overdrive with a high stall but lock up converter & a q-jet. If it had 3 speed trans, no lock up converter, & a square bore carb with the same gears it would have been lucky to have pulled off 12 mpg. It would not have been faster either.

 

[jospooner83cutlass]

okay but whats the point of having it if your going to keep your foot out of it, thats just no fun 8)

 

[GT_80]

you should put the old huge cadillac 500 mufflers on it, the ones that are quiet but flow well, keep a stock hood and steel rims or wire spoke hub caps on wide wheels, and just make a NASTY sleeper! Pull up next to a guy at the light wearing a golf hat and big blue blocker sunglasses, then blow him away!!! LOL

 

[DoubleV]

okay but whats the point of having it if your going to keep your foot out of it, thats just no fun 8)

We're just telling you how it is. You asked about milage which implies you're the one who cares about it. If milage is a concern to you then you need to take the proper steps to help you achieve that, and keeping your foot out of it is numero uno. Even fuel efficient cars will suck on gas if you're romping on them all the time.

 

[jospooner83cutlass]

i like the way you think GT_80. i think screw gas milage because in my lifetime everything will probly go electric 🙁 may as well use gas well it is still around