Quote:
Originally Posted by dayj1
I centered the transmission output shaft on my '72 swap and the driveshaft is centered in the hole through the crossmember. I'm amazed that Holley put that in their instructions. 1/16" in engine placement isn't going to make any difference one way or another.
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Well, there might be room for debate here. Ujoints don't like being head-on, they need a certain amount of flexion to not bind the yolks. Offsetting the motor that tiny bet helps prevent the driveshaft from ever going dead-nuts straight to the output shaft and rear end. Normally, the amount of vertical drop in the driveshaft angle does this just fine, but on bagged trucks with 1 peice ujoints, its possible to get a drive angle so flat that you can actually bind the ujoints up.
I'm guessing this is something thats mostly prevalent on trucks with rear ends which are centered. If you look carefully on late model RWD vehicles, the rear end is actually offset just slightly to one side or the other (in trucks, this is sometimes to ease the angle of departure from 4wd transfer cases).
My $1 on the topic. Holley might have some other crazy reason for doing it, but thats the only logical one I can deduct.