View Full Version : big block motor swap
jason26933
04-10-2009, 05:03 PM
I have a 67 chevy impala convertible with a 350 sb that was put in place of a 327. So the Impala was originally a sb 327 car. I am new to the muscle car world. I am looking at a gm perf. parts 454 to put in the Impala. I know I will have to buy new motor mounts and bb headers. Is there any major concerns I should be aware of or will it be a pretty easy swap. Any suggestions or transmissions. I would like to get a transmission with overdrive but was told a TH 400 is more affordable. Will I have to move the transmission mount and if so is there different mounting spots on this particular car?? Any suggestions with my questions or an ideas would be greatly appreciated. I am nervous and somewhat fearful I may be getting in over my head. Due have numerous friends with more experience than me that are willing to help. Nervous in OHIO.[/b]
fla1976
04-10-2009, 05:08 PM
I would see if I could borrow a BBC just to fit it up. I am thinking there may be a problem with the oil pan clearance. There is plenty of room under the hood.
BEAST477
04-10-2009, 05:11 PM
It wont be any real problems. I did basically the same swap 30+ years ago in a "66 Impala. Like you said different motor mounts and i think the frame has multiple holes for putting the cross member where you need it. I would put the turbo 400 in and hope its got rear gears in the 3.23:1 range and let the torque of the big block work for you.
radicalz
04-12-2009, 11:04 PM
I have a 67 chevy impala convertible with a 350 sb that was put in place of a 327. So the Impala was originally a sb 327 car. I am new to the muscle car world. I am looking at a gm perf. parts 454 to put in the Impala. I know I will have to buy new motor mounts and bb headers. Is there any major concerns I should be aware of or will it be a pretty easy swap. Any suggestions or transmissions. I would like to get a transmission with overdrive but was told a TH 400 is more affordable. Will I have to move the transmission mount and if so is there different mounting spots on this particular car?? Any suggestions with my questions or an ideas would be greatly appreciated. I am nervous and somewhat fearful I may be getting in over my head. Due have numerous friends with more experience than me that are willing to help. Nervous in OHIO.[/b]
I did my swap from small to BBC used the same motor mounts just sits a little back from original maybe about 1/2 inch closer the the firewall...can even fit a GM HEI in there too. Your engine bay has enough room to house a jet engine if you wanted to put that in place. Should be no problem at all installin a BBC under your hood....but have new mounts in place since then....so if your planning on the new mounts do it while you have the chance....I also have a built TH350 in back of mine with trans brake, 3800 converter....it is all in your planning
Drtmod5
04-13-2009, 08:03 AM
I did this swap on my S-10! If it works there you should have no problem on yours. I didn't have to swap anything as all mounts went back where they were. The only major change you will see is that the BBC will extend forward (toward radiator) @ 4-4 1/2 inches closer than a SBC. Good luck. Dave
ashbros
04-13-2009, 11:17 AM
You have an open field under the hood with plenty of room to play. Throw that BBC in there and slap a big fat blower on it. If she don't run atleast she'll look mean as hell.