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roj2323 · 11-22-2004, 11:58 PM

--How to adapt 73-87 engine mounts to a 67-72 frame--

This is an easy and fast mod. With the proper tools and about an hour you will be able to use a more modern, stronger and safer engine mounting system.

Tools you will need
-drill
-drill bits
-1/16
-7/16 or a UNIBIT
-Dremel tool with cut off bit
-file
-clamp or fabric ratchet strap

Parts you will need

-frame brackets, I got mine at a junk yard for $10
Part #'s 6271362, 6271361
-engine to engine mount brackets I got mine out of a junk
Part #14037875
-Engine mounts- got mine from Carquest. asked for 85gmc mounts
Sorry no part number "will update if given"
-14 grade8 3/8x1in bolts
-14 lock nuts or nyloc's
-28 washers

The first thing you will need to do is drill a 1/16 hole 1/8 of an inch from the side of the current holes. Please see the image above for the locations @ yellow dots". There will be a total of 4 per bracket.

Next use your 1/16 holes as guides and enlarge the holes to match the originals. I used a UNIBIT since it was handy but a 7/16 bit will work as well.

Next use your Dremel tool with the cut off bit and cut the points out between the holes. This will create the oblong holes that will provide the clearance needed for the install. Clean the hole out using the 7/16 drill bit and or file smooth as needed.

After the above modifications it should look like this:

Part 2

Remove the old mounts from your frame and set the new ones on as seen below. The bottom bolt holes don't exist yet but slide bolts into the top holes so they don't fall. Do not tighten.

After you have set the brackets on the frame slide them all the way towards the back of the frame and tighten the bolts. The bottom of the brackets will float about a 1/4in off the cross member after you tighten them. Because of this you will have to either clamp them or use a cloth ratchet strap to pull them down so they touch the cross member. Next drill 2 holes on either side of the cross member inside the mounting holes making sure you drill them on the front half of the hole “the red dots in the above picture". Doing this will give you the ability to slide the bracket forward at least 1/2 inch.
Install your lower bolts and tighten. Remove your clamp or ratchet strap and you’re done.

You should now be able to install your engine using the newer mounts as seen below:

As an extra perk of using the newer engine mounts you don't have to drill any holes to install the Trans cross member for a 700r4 late model trans. You will however have to drill holes for the shift linkage after you line it up. I used a piece of pipe.

Heres the link for the Trans install photos as well as extra engine mount photos. http://www.maj.com/gallery/roj2323

OnDrew Hartigan

p.s. it took me longer to do this write up than it did to do the mod. go figure! =)

11-22-2004, 11:58 PM	#1
roj2323 Senior Member Join Date: Mar 2004 Location: Somewhere Posts: 985	--How to adapt 73-87 engine mounts to a 67-72 frame-- --How to adapt 73-87 engine mounts to a 67-72 frame-- This is an easy and fast mod. With the proper tools and about an hour you will be able to use a more modern, stronger and safer engine mounting system. Tools you will need -drill -drill bits -1/16 -7/16 or a UNIBIT -Dremel tool with cut off bit -file -clamp or fabric ratchet strap Parts you will need -frame brackets, I got mine at a junk yard for $10 Part #'s 6271362, 6271361 -engine to engine mount brackets I got mine out of a junk Part #14037875 -Engine mounts- got mine from Carquest. asked for 85gmc mounts Sorry no part number "will update if given" -14 grade8 3/8x1in bolts -14 lock nuts or nyloc's -28 washers The first thing you will need to do is drill a 1/16 hole 1/8 of an inch from the side of the current holes. Please see the image above for the locations @ yellow dots". There will be a total of 4 per bracket. Next use your 1/16 holes as guides and enlarge the holes to match the originals. I used a UNIBIT since it was handy but a 7/16 bit will work as well. Next use your Dremel tool with the cut off bit and cut the points out between the holes. This will create the oblong holes that will provide the clearance needed for the install. Clean the hole out using the 7/16 drill bit and or file smooth as needed. After the above modifications it should look like this: Part 2 Remove the old mounts from your frame and set the new ones on as seen below. The bottom bolt holes don't exist yet but slide bolts into the top holes so they don't fall. Do not tighten. After you have set the brackets on the frame slide them all the way towards the back of the frame and tighten the bolts. The bottom of the brackets will float about a 1/4in off the cross member after you tighten them. Because of this you will have to either clamp them or use a cloth ratchet strap to pull them down so they touch the cross member. Next drill 2 holes on either side of the cross member inside the mounting holes making sure you drill them on the front half of the hole “the red dots in the above picture". Doing this will give you the ability to slide the bracket forward at least 1/2 inch. Install your lower bolts and tighten. Remove your clamp or ratchet strap and you’re done. You should now be able to install your engine using the newer mounts as seen below: As an extra perk of using the newer engine mounts you don't have to drill any holes to install the Trans cross member for a 700r4 late model trans. You will however have to drill holes for the shift linkage after you line it up. I used a piece of pipe. Heres the link for the Trans install photos as well as extra engine mount photos. http://www.maj.com/gallery/roj2323 OnDrew Hartigan p.s. it took me longer to do this write up than it did to do the mod. go figure! =) Last edited by N2TRUX; 02-14-2010 at 11:36 AM.