Question on installing 72 bbc mounts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

LT4XTREME · 02-23-2011, 10:44 AM

I'm working on a 71 swb fleetside that originally had a small block with a 3 speed. The PO swapped the 3 speed for a 4 speed now I'm switching it to a BBC th400. I got a set of 72 BBC frame and engine mounts but I'm having trouble lining up the frame mounts. Do I have to drill the front lower hole in the 71 crossmember for the 72 bbc mounts to bolt in? thanks in advance!!

Jason

sameyrasmea72 · 02-23-2011, 02:06 PM

I have heard that you do have to drill at least one hole in the cross menber to add 72 BB mounts to a non BB front end. The top two holes should line up, just make sure you use the correct location on the top two. I might be able to find a pic of the top location if you need it......Jason

LT4XTREME · 02-23-2011, 03:44 PM

Thanks I had a pic but it wasn't clear about the front lower hole. I'll feel a little better drilling the hole in it now.

**leddzepp** · 02-23-2011, 04:05 PM

since you have a 71 x-member, you need to drill out that additional hole. 72 x-members had the additional hole there whether or not the truck came with a bbc or sbc. no big deal, they will still fit perfectly.
Posted via Mobile Device

02-23-2011, 10:44 AM	#1
LT4XTREME Registered User Join Date: Nov 2004 Location: MINERAL WELLS WV Posts: 143	Question on installing 72 bbc mounts I'm working on a 71 swb fleetside that originally had a small block with a 3 speed. The PO swapped the 3 speed for a 4 speed now I'm switching it to a BBC th400. I got a set of 72 BBC frame and engine mounts but I'm having trouble lining up the frame mounts. Do I have to drill the front lower hole in the 71 crossmember for the 72 bbc mounts to bolt in? thanks in advance!! Jason

02-23-2011, 02:06 PM	#2
sameyrasmea72 Senior Member Join Date: Aug 2003 Location: Lubbock, Texas Posts: 2,443	Re: Question on installing 72 bbc mounts I have heard that you do have to drill at least one hole in the cross menber to add 72 BB mounts to a non BB front end. The top two holes should line up, just make sure you use the correct location on the top two. I might be able to find a pic of the top location if you need it......Jason __________________ 72 Cheyenne Super 80 Silverado Blazer 2wd

02-23-2011, 03:44 PM	#3
LT4XTREME Registered User Join Date: Nov 2004 Location: MINERAL WELLS WV Posts: 143	Re: Question on installing 72 bbc mounts Thanks I had a pic but it wasn't clear about the front lower hole. I'll feel a little better drilling the hole in it now.

02-23-2011, 04:05 PM	#4
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 20,048	Re: Question on installing 72 bbc mounts since you have a 71 x-member, you need to drill out that additional hole. 72 x-members had the additional hole there whether or not the truck came with a bbc or sbc. no big deal, they will still fit perfectly. Posted via Mobile Device __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man RIP FleetsidePaul



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