[Lee]

Background, '68 Sprint 6 convertible, previously had a 200-4R installed with a G-force crossmember.

I bought the V-8 frame mounts and poly engine mounts from our host, Ames Performance. No instructions, but laying out the parts on the crossmember, I only saw ONE way they could possibly be installed.

The Poly motor mounts appear to be identical, so either can go on either side.

I have the motor sitting in place, the motor mounts are against the rear stop of the frame mounts. I had to remove the bolts connecting the tranny to the crossmember to get the tranny to wiggle enough to mate to the engine, and now have the 4 lower tranny bolts snugged to the motor.

Now, the tail of the tranny is angled toward the driver's side of the car. I'm suspecting the car was wrecked and maybe the crossmember and/or frame got tweaked. As it sits, the driver's side of the motor can't move back, as it is against the frame mount stop, and the passenger side engine/frame mount bolt is about as forward as it can go.

Am I missing something?? Anyone else had similar issues?

Oh, looks like the front of the oil pan is touching the crossmember as well.

[Donovan]

While doing a swap I learned that Pontiac biased the V8 cars off-center to make it fit. I think if you look at the steering box it's really close even so. But to accomplish this the frame mounts are not symetrical AND the crossmember was drilled off center. If you compare a trans crossmember from a Camaro to a Firebird you'll see the slight difference.

Based on the description I would expect that your G-force crossmember is drilled on-center like a chevy and you're having some trouble mixing and matching parts. The Sprint would have been centered since it doesn't need the room

[Donovan]

http://www.camaros.org/trans.shtml

Scroll down to see the details

[Lee]

Thanks for the reply Donovan!

I looks like I got it sorted out. I had to slot the bolt holes on both motor mounts, which allowed the motor to rotate some. I also had to elongate the holes in the frame mounts, which then gave just enough additional rotation to get the motor to sit square. As viewed from above, before the mods, the motor was not just situated off-set, it at a diagonal - as in this situation | / |

The G-force crossmember fits perfectly, so it may have been at an angle with the Sprint 6 installed.

I just test fit the Doug's headers, and they seem to fit as designed. That suggests to me that the motor IS properly square.

Crazy that I had to modify both the engine and frame mounts. I have to wonder if the parts tolorances are THAT sloppy, or if the car itself has a tweaked frame.

[mysticmissle]

I did a 6 swap to a 455 and encountered issues w the frame mounts also
I think it’s the repro frame mounts that caused the bulk of the head aches and also had to slot the big hole to get it to sit where I wanted
Nice car!