I6 vs. V-8 motor mount clarity? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

'70 C/10 SS500 · 08-28-2003, 03:50 PM

Well, the Caddy 500 install hit it's first big setback, wrong motor mount brackets. My staggered I6 brackets don't line up with the big Caddy's front located mounts. Actually, the pass. side bracket does pretty darn good, but the further back driver side is too far back to work. I'd like some clarity about the differences between I6 and V-8 brackets. I hear "I6/V-8 postion" thrown around here alot, but don't really know FOR SURE what that really means. I have staggered ones, is that what is know as "I6 position?" Are V8 brackets both in the forward pos., or rear? Some clarity for the record would do me wonders.

For my Caddy motor, I definately need front frame brackets, WHAT ARE THEY? I have universal brackets (steel plates) that are supposedly for this motor swap, but they aren't doing much good without the proper frame brackets.

If I do need to get a specific frame bracket, is there any way to get them other than searching the junk yard?

Help me get this beast in there!

rambler · 08-28-2003, 04:12 PM

You may want to also post this in the Engine & Drivetrain forum, there is a post now labled "engine location" that talks a little bit about the conversion form I6/V8 I'm looking at doing that in a few months for the 68 but doing a 350 not 500.. good luck

Tx Firefighter · 08-28-2003, 04:31 PM

If your 6 cyl brackets are not even with each other, that is, one is farther back, than the other, you must have had a 292 6 cylinder.

People say 6 cyl or 8 cyl brackets, but they forget that the 292 6 cyl uses a different right side bracket than either the other 6 cyls or v8s. The holes in the frame are for 6 cylinder in the rear set, and 8 cylinder in the front set.

crazy longhorn · 08-28-2003, 07:24 PM

I did this in the Longhorn......the Cad mounts are way foward from anything else GM. I used a set of bracket/clamshells from a 78 sedan deville, & mounted them on 73 up truck stands......even at that, they needed a chunk of 3/8 flat plate tween the clamshell & the stand, as the mounts were a bit ahead to be a direct weld down on the stands. I dont have any good shots of the mounts, but that Caddy fit pretty nice in the Longhorn. There should be a shot or 2 in web shots.... http://community.webshots.com/user/hotrodhorn crazyL

Longhorn Man · 08-28-2003, 10:44 PM

I did mine with no kit, and it is sitting in there pretty good. It might be a bit high, but that helps on the launch.
pics and description in my caddy swap site listed in signiture.

08-28-2003, 03:50 PM	#1
'70 C/10 SS500 Registered User Join Date: Jun 2003 Location: Chandler, AZ Posts: 130	I6 vs. V-8 motor mount clarity? Well, the Caddy 500 install hit it's first big setback, wrong motor mount brackets. My staggered I6 brackets don't line up with the big Caddy's front located mounts. Actually, the pass. side bracket does pretty darn good, but the further back driver side is too far back to work. I'd like some clarity about the differences between I6 and V-8 brackets. I hear "I6/V-8 postion" thrown around here alot, but don't really know FOR SURE what that really means. I have staggered ones, is that what is know as "I6 position?" Are V8 brackets both in the forward pos., or rear? Some clarity for the record would do me wonders. For my Caddy motor, I definately need front frame brackets, WHAT ARE THEY? I have universal brackets (steel plates) that are supposedly for this motor swap, but they aren't doing much good without the proper frame brackets. If I do need to get a specific frame bracket, is there any way to get them other than searching the junk yard? Help me get this beast in there!

08-28-2003, 04:12 PM	#2
rambler MOVE OVER Join Date: Jun 2002 Location: Warrensburg, MO Posts: 5,470	You may want to also post this in the Engine & Drivetrain forum, there is a post now labled "engine location" that talks a little bit about the conversion form I6/V8 I'm looking at doing that in a few months for the 68 but doing a 350 not 500.. good luck __________________ No matter where you are..... There you are... Buckaroo Banzi

08-28-2003, 04:31 PM	#3
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	If your 6 cyl brackets are not even with each other, that is, one is farther back, than the other, you must have had a 292 6 cylinder. People say 6 cyl or 8 cyl brackets, but they forget that the 292 6 cyl uses a different right side bracket than either the other 6 cyls or v8s. The holes in the frame are for 6 cylinder in the rear set, and 8 cylinder in the front set. __________________ I'm on the Instagram- @Gearhead_Kevin

08-28-2003, 07:24 PM	#4
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	I did this in the Longhorn......the Cad mounts are way foward from anything else GM. I used a set of bracket/clamshells from a 78 sedan deville, & mounted them on 73 up truck stands......even at that, they needed a chunk of 3/8 flat plate tween the clamshell & the stand, as the mounts were a bit ahead to be a direct weld down on the stands. I dont have any good shots of the mounts, but that Caddy fit pretty nice in the Longhorn. There should be a shot or 2 in web shots.... http://community.webshots.com/user/hotrodhorn crazyL __________________ 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....

08-28-2003, 10:44 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	I did mine with no kit, and it is sitting in there pretty good. It might be a bit high, but that helps on the launch. pics and description in my caddy swap site listed in signiture.



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