[NHRASuperStock455SD]

Originally Posted by Skip Fix

Lynn I think I even have an 81 assembly manual that shows with holes for what GM motor

Skip, can u email me? Also, do you have part numbers for the clam shells?

[Grand73Am]

I said this earlier, but maybe you missed it:

Originally Posted by Grand73Am

Yes, the firebird/TA 301 clamshell motor mounts are the same as the clamshell 400 motor mounts.

Question is whether you have the correct firebird/TA engine brackets? The part numbers that should be on the brackets are 496892 and 496893.

The clamshell motor mounts (that bolt to the frame) can be bought from any parts store, so a GM parts number isn't needed. You can find them on any parts store website by doing a search for motor mounts for any 75-81 TA with a Pontiac engine. Even the 301 Pontiac and 403 Olds use the same motor mounts as the 400/455 Pontiac. The GM numbers are 10003684 and 10003685, but GM doesn't have them any more, so the numbers aren't very helpful.

The correct engine brackets(the brackets that bolt to the engine) is what you may need, and I gave the part numbers for them above. GM doesn't have them anymore either, but the part numbers are stamped on the brackets, so you can tell if the ones you have are correct or not. You'll have to look closely at the brackets to find the numbers, but they should be stamped on them. If your brackets don't have 496892 stamped on the right one, and 496893 on the left, they are the wrong brackets, and you'll need to get the correct brackets. So the numbers are helpful for that.

[NHRASuperStock455SD]

Thanks Steve.

Here is the first prototype passenger side tubular exhaust. The OEM is less than 1.5 runners and very small collector. Ours are 2 inch tubes and 3 inch Vband. This makes for a difficult transition from about 4 1/4 inches down to 3 inches making the collector long. We are now trying to cut the length in 1/2. We can also do 3 1/2 Vband making it equally as short, but most want to hook up with 3 inch piping.

[Skip Fix]

Lynn I'll pull it out, scan it and FAX it. Often they have part #s on it.

And my 81 had a 301 Turbo and the 400 in it now is using the same mounts.

[1971WARBIRD]

remember the early 70-74 used solid mount to the frame and a rubber to the block, where your later used the solid to the block and rubber to the frame. I am not sure how this will effect what you are trying to do. I have never tried putting the later clam shells in an early 70's bird.

[Skip Fix]

here are assembly manual pictures. LG4 is Chevy Motor, LD5 buick, LS5 2BBL Pontiac,L37 4BBL Pontiac, LU8 Turbo Pontiac.