Big Block install Question... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**67 cst swb** · 06-02-2008, 08:49 AM

A friend of mine is installing a Chevy Big Block.
Our question is:
We are using the factory BB mounts from a 74 big block donor truck... brackets, rubber mounts, cups..
The problem is it seems to sit very high above the crossmember (approx. 4-1/2" above crossmember. Very much so higher than a small block '68 we compared to he is currently driving...
Any thoughts or input here...

Longhorn Man · 06-02-2008, 04:29 PM

not to be a smart ass... but my thoughts are to locate the correct towers and mounts off a 68 - 71, or a 72 truck.

Jtrux · 06-02-2008, 04:49 PM

Quote:

Originally Posted by Longhorn Man

not to be a smart ass... but my thoughts are to locate the correct towers and mounts off a 68 - 71, or a 72 truck.

Agreed. I put a 396 in my blazer a few years ago and used factory small block mounts to the factory crossmember, had ZERO issues with that part.

Adctfull1 · 06-02-2008, 05:36 PM

i used stock small block towers & mounts also, but i pushed the whole works back as far as i could for weight transfer purposes

**67 cst swb** · 06-02-2008, 09:30 PM

Quote:

Originally Posted by Longhorn Man

not to be a smart ass... but my thoughts are to locate the correct towers and mounts off a 68 - 71, or a 72 truck.

First... I'm not a B/B guy, but... I was under the impression that 72, was the same as 73-later....

Second... if we used the SB towers, do you need to modify them in any way? Aren't Facory BB towers hole larger for the motor mount bolt.
And... which rubber mount did you use?

Longhorn Man · 06-02-2008, 09:36 PM

the towers in a 72, are a one year only item. They are better than the 68 - 71, and fit properly unlike the 73 - 87. As for the actual mounts... I think the clamshell BBC mount is in fact the same 72 - 87.
I wasn't trying to be a PITA, which it looks like I was coming across that way. Sorry.

breeh · 06-03-2008, 12:53 AM

I know that I have seen posts where people have successfully retrofitted the 73 and later BBC motor mounts. I haven't had the chance to compare a '72 to a '73 and up but from the pictures that I have seen they sure look very similar. I am sure that someone will chime in sooner or later who has experience with this retrofit.

**67 cst swb** · 06-03-2008, 01:00 AM

Quote:

Originally Posted by Longhorn Man

the towers in a 72, are a one year only item. They are better than the 68 - 71, and fit properly unlike the 73 - 87. As for the actual mounts... I think the clamshell BBC mount is in fact the same 72 - 87.
I wasn't trying to be a PITA, which it looks like I was coming across that way. Sorry.

no prob

06-02-2008, 08:49 AM	#1
67 cst swb Senior Member Join Date: Nov 2001 Location: Rapid City, SD Posts: 2,281	Big Block install Question... A friend of mine is installing a Chevy Big Block. Our question is: We are using the factory BB mounts from a 74 big block donor truck... brackets, rubber mounts, cups.. The problem is it seems to sit very high above the crossmember (approx. 4-1/2" above crossmember. Very much so higher than a small block '68 we compared to he is currently driving... Any thoughts or input here... __________________ My Trucks: 1967 Chevrolet Short Wide Box 327 TH350 9" w/3.90 gears paint will be White - Current Project 1967 Chevrolet Custom LWB 283 TH400 3.73 Posi, no-AC, no-PS, no-PB, bench-seat, small-window - mostly orig driver 1967 Chevrolet CST LWB originally a 327 TH400 3.73 Posi AC PS PB, had Buddy Buckets, Small Window - parts truck 1967 Chevrolet CST LWB, 283 MT 3.73 had Buddy Buckets, Panoramic Window - parts truck 2001 Chevrolet 3500 2WD Crew Cab Dually 8.1L Allison White Last edited by 67 cst swb; 06-02-2008 at 08:50 AM.

06-02-2008, 04:29 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Big Block install Question... not to be a smart ass... but my thoughts are to locate the correct towers and mounts off a 68 - 71, or a 72 truck.

06-02-2008, 05:36 PM	#4
Adctfull1 Registered User Join Date: Jun 2007 Location: wy Posts: 12	Re: Big Block install Question... i used stock small block towers & mounts also, but i pushed the whole works back as far as i could for weight transfer purposes

06-02-2008, 09:36 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Big Block install Question... the towers in a 72, are a one year only item. They are better than the 68 - 71, and fit properly unlike the 73 - 87. As for the actual mounts... I think the clamshell BBC mount is in fact the same 72 - 87. I wasn't trying to be a PITA, which it looks like I was coming across that way. Sorry.

06-03-2008, 12:53 AM	#7
breeh Recovering 67-72 Addict Join Date: Oct 2000 Location: North Bend, WA Posts: 1,788	Re: Big Block install Question... I know that I have seen posts where people have successfully retrofitted the 73 and later BBC motor mounts. I haven't had the chance to compare a '72 to a '73 and up but from the pictures that I have seen they sure look very similar. I am sure that someone will chime in sooner or later who has experience with this retrofit. __________________ 68 Short Fleet 4x4; 427; BTO Level 3 700R4; NP205; Dana 60 front and rear; 4" lift with 35's; Disc brakes; AGR variable ratio steering; factory bucket seats; factory tach and tilt. "Friends call me cruzer cuz I like fast cars and fast women"



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