ClassicOldsmobile.com - View Single Post - 307

J-(Chicago) · 02-24-2008, 08:36 AM

If you are using the 9'' tail shaft, you may have to move your crossmember, and if you are upgrading to an 8.5'' rear end you will have to get your driveshaft resized. I am doing a similar project this spring. I believe you can use your 307 motor mounts and it will drop in ok. 455 is an inch wider at the intake, but the motors are almost the same size. I'm not sure about A body headers on a G body, but this swap has been done a thousand times, and I'm sure someone else can clarify for you.
The guys on Realoldspower.com probably do this swap weekly. You'll probably find info on everything over there.

02-24-2008, 08:36 AM	#4 (permalink)
J-(Chicago) Seasoned beater pilot. Join Date: Jan 2007 Location: Chicago Posts: 1,646	If you are using the 9'' tail shaft, you may have to move your crossmember, and if you are upgrading to an 8.5'' rear end you will have to get your driveshaft resized. I am doing a similar project this spring. I believe you can use your 307 motor mounts and it will drop in ok. 455 is an inch wider at the intake, but the motors are almost the same size. I'm not sure about A body headers on a G body, but this swap has been done a thousand times, and I'm sure someone else can clarify for you. The guys on Realoldspower.com probably do this swap weekly. You'll probably find info on everything over there. __________________ I'd rather have a numbers matching poker hand.