Motor Mounts/Motor Positioning

[lilshep2010]

Long story short, I'm installing a new motor in my 71 and running into a few issues. My stock motor mount brackets were a little rough (someone decided to use a torch and make one of the holes a bit bigger) so I replaced them with the brothers tubular mounts. They are similar to the POL design (almost identical actually).

Whenever I went to install the motor, we realized that the brothers mounts moved the motor back farther than the old ones. So we unbolted the trans and pushed everything back to bolt up the motor. Then we realized that the driveshaft was bottomed out in the trans and was obviously too long.

So the next step is to either buy new motor mounts or modify the driveshaft.

A little backstory that may be helpful: with the original mounts I was having header issues. I've got longtube heddman headers that were rubbing the backside of the a-arms. With the new mounts installed I've got about an inch of space. Basically I'm not completely sure I had the right mounts originally. They appear to be 67-72 mounts, but they aren't fitting right. Also, they have about an inch of forward offset from the center and the brothers mounts have about a a half inch of forward offset.

What are everyone's thoughts on this?

[kwmech]

Big block, small block? Are the new mounts bolted in the same spot as the original?

[lilshep2010]

Sorry about that. It's a small block. The mounts are in the exact same position (forward position). As I said before, the only difference appears to be the difference in the offset in the motor mount brackets.

[michael bustamante]

couldnt you reposition the motor mounts and scoot em foward?

[lilshep2010]

Originally Posted by michael bustamante

couldnt you reposition the motor mounts and scoot em foward?

I could, but I would rather not drill new holes into the frame.

[lilshep2010]

I guess the best question may be where should the motor be sitting? That would give me a better idea of what the issue is and what needs to be modified.
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[kwmech]

If they are bolted in the same position but are offset back, then you got the wrong mounts, you got the big block version. The big block mounts move the engine back about 1-1/2' just like the factory mounts

[lilshep2010]

Originally Posted by kwmech

If they are bolted in the same position but are offset back, then you got the wrong mounts, you got the big block version. The big block mounts move the engine back about 1-1/2' just like the factory mounts

After measuring and looking at the invoice, it looks like I got the right mounts. It just looks like the stock mount's offset and the brothers mount's offset are different. I asked brothers if their mounts moved the engine from the stock location. They said it wouldn't, but it doesn't look like that's the case. Appears to be the typical issues when working with aftermarket parts.

[firedemon]

I got the same mounts from cpp they say big or small block so maybe they set them up for the big block I haven't found the engine for mine yet so I haven't had a chance to use em but the trans mount is offset also and wouldn't line up with the holes in the frame with my long tail t400 so I had to use the factory crossmember I'm hoping when I get the motor it will all work out

[lilshep2010]

Originally Posted by firedemon

I got the same mounts from cpp they say big or small block so maybe they set them up for the big block I haven't found the engine for mine yet so I haven't had a chance to use em but the trans mount is offset also and wouldn't line up with the holes in the frame with my long tail t400 so I had to use the factory crossmember I'm hoping when I get the motor it will all work out

Are they the tubular ones or the fabricated sheet metal ones? Can you measure the offset of them?
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[firedemon]

the tubeular onestape measure says 1 3/8

[firedemon]

minw were also listed from 64 or 5 to 67 it said 68 and newer are different for some reason . but like I said I haven't used them yet so I'm not sure and I have a six in it now so everything is diffrent

[lilshep2010]

Originally Posted by firedemon

minw were also listed from 64 or 5 to 67 it said 68 and newer are different for some reason . but like I said I haven't used them yet so I'm not sure and I have a six in it now so everything is diffrent

Yours are definitely more offset than mine. On the brothers website they say they are for 68-72, but the paperwork that came with them says they are for 63-72.