73 up BB frame mounts on 71? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

71BB_LWB · 11-16-2002, 01:46 AM

Can anyone shed some light on this, I was told that with only slight frame mods I can use the newer style towers and then I can use the better stronger mounts.
Has anyone done this swap, and can you give me any guideance?
Thanks
Dan

71BB_LWB · 11-16-2002, 02:48 PM

ttt

tom hand · 11-16-2002, 02:48 PM

I have never done that exact swap but since no one has replied I will give you some advice from numerous GM swaps I have done. 73 up mounts look almost identical to 72 BB mounts. The frame is almost identical which is why you can change out the front crossmember buy only drilling a couple of holes. I would bet you can install the 73 up mounts buy only drilling holes also, the trick is laying out where they go. A trick I have used when swapping motors is to have the motor and transmission bolted together, bolt the motor mounts and the towers to the motor and set the whole thing in the truck. When you get the transmission mount lined up, set it down and you can see where the holes need to be drilled. To mark the holes white spraypaint works well. Remove motor, drill holes, install towers, reinstall motor. If nothing else my reply will get someone else fired up with better advice. Good Luck

crazy longhorn · 11-16-2002, 03:12 PM

That sounds like good advice Tom has there. I havent done a BB chev that way, but did install a 455 olds on the late 70's stands in my 69, with 5.7 deisel mounts & brackets. the stands sit pretty well on the frame , & just need to be drilled. I opted to just weld the bottom of the stands to the crossmember to save the step of pulling the eng back out to drill. Good luck

**Desert Rat** · 11-17-2002, 11:40 AM

I have a set of mounts i took out of a 73 SWB 454 truck i bought for the motor,they are similar to 72 except bolt holes are further apart on top,so youll have to drill.I think the SB and BB ones are the same?I put a BBC in my 79 Blazer with the 350 mounts.but i have a set of them from the 454 truck $25.with the engine clamshells,shipping is the kicker its a few over $20

11-16-2002, 01:46 AM	#1
71BB_LWB Thread Killer! Join Date: Feb 2002 Location: Chandler, Arizona Posts: 235	73 up BB frame mounts on 71? Can anyone shed some light on this, I was told that with only slight frame mods I can use the newer style towers and then I can use the better stronger mounts. Has anyone done this swap, and can you give me any guideance? Thanks Dan

11-16-2002, 02:48 PM	#3
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I have never done that exact swap but since no one has replied I will give you some advice from numerous GM swaps I have done. 73 up mounts look almost identical to 72 BB mounts. The frame is almost identical which is why you can change out the front crossmember buy only drilling a couple of holes. I would bet you can install the 73 up mounts buy only drilling holes also, the trick is laying out where they go. A trick I have used when swapping motors is to have the motor and transmission bolted together, bolt the motor mounts and the towers to the motor and set the whole thing in the truck. When you get the transmission mount lined up, set it down and you can see where the holes need to be drilled. To mark the holes white spraypaint works well. Remove motor, drill holes, install towers, reinstall motor. If nothing else my reply will get someone else fired up with better advice. Good Luck __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

11-16-2002, 03:12 PM	#4
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	That sounds like good advice Tom has there. I havent done a BB chev that way, but did install a 455 olds on the late 70's stands in my 69, with 5.7 deisel mounts & brackets. the stands sit pretty well on the frame , & just need to be drilled. I opted to just weld the bottom of the stands to the crossmember to save the step of pulling the eng back out to drill. Good luck __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

11-17-2002, 11:40 AM	#5
Desert Rat Senior Member Join Date: Dec 1999 Location: Darrington, Washington Posts: 3,963	I have a set of mounts i took out of a 73 SWB 454 truck i bought for the motor,they are similar to 72 except bolt holes are further apart on top,so youll have to drill.I think the SB and BB ones are the same?I put a BBC in my 79 Blazer with the 350 mounts.but i have a set of them from the 454 truck $25.with the engine clamshells,shipping is the kicker its a few over $20



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