I need a shorter A518!

Backstory-

My older brother and myself have been helping my younger brother install a '97 360 magnum with a '95 A518 into my younger brothers '67 A-100 window van. The van originally had a LA318 and a short tail 727 with the top mount.

Problem-

When we started the swap we didnt realize (all of us are chevy guys) that there is a short tail 727 and a regular length. The difference from the short tail 727 to the regular length A518 is substantial- approx. 7".

We had problems mounting the engine as we thought the LA318 mounts would work but they will not, so we are going to swap to LA360 mounts from a 1/2 ton pickup. But with the engine installed roughly where it goes using the 318 mounts, the engine is correct front to back and level but it is shifted over to the drivers side, the tail shaft seal of the trans is 12.5" from the center of the u joint on the rear end. With the yoke installed in the trans with 1" of pullout, this leaves a drive shaft length of 8.75".

The trans output is about level with the rear end, so at max up travel of 3.5" until the rear end hits the bump stops, this would make the drive shaft at an approx angle of 22°. This is too much. We could limit suspension travel down to 2.5" but that isn't an attractive solution because the eventual plan is to lower the van down around 3" in front and 4" in rear. So at 7.5" down from where it is now, that would make an angle of ~41°!

Basically the drive shaft is just too short. Looking at the stock 727 transmission, the yoke bolts on the trans output shaft and all the slip is in the shaft.

This got us thinking....

Questions-

Is a 4wd A518 shorter than a 2wd? Anyone know the length from the leading edge of the bellhousing to the trailing edge where a transfer case would bolt to? We are hoping they are ~7" shorter. I'm attempting to research this myself but coming up empty.

It seems like we could swap on a 4x4 overdrive unit to shorten the A518 up and machine a plate with a high speed seal to bolt where a transfer case would. Then find a mating hub or yoke to bolt on the output shaft and attach a flange style drive shaft yoke on that which can take more angle. Of course, a slip yoke would need to be used in the drive shaft like stock.

Anyone think this is a decent plan/idea? Any other ideas besides to s**** the overdrive?

Thanks!
-Dustin

 

Unfortunately all OD units will be the same length and modifying the FWD unit, while doable, will no doubt get expensive.
I suggest that for the SWB A-100 you go back to a short van style trans and live without the OD. The 360 has the torque to pull a 2.45 gear if hi-way travel is the big factor.

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well I need to learn about using CV joints. I think they may take more angle?