Building a ‘29 A Phaeton with my sons and grandsons. We’re trying to use parts we already have as much as possible. The original banger is freshly rebuilt, so we’re going to run it. We’ve got a T5 to put behind it. Our T5 has 3.97 first gear and .72 overdrive ratio. We were going to use the original A rearend, but it turned out to be junk. We’re are now using an 8 inch we already had. Finally, my question - we have two gear sets for the 8 inch, a 2.79, and a 4.10. Which would be better for all around drive ability? I think something in between might be optimal? Or could we be OK with one of these?
That 2.79 gear set would be an absolute turd with the banger. My Merc flatty with a t5 had a banjo with 3.78 gears and it did well. Got great mileage and accelerated rather well outta the hole.
That's not an ideal trans. And the 2.79 rear gear won't work with the .72 OD. The .72 OD with the 4.10 rear gives you a 2.95 overall. Not sure how often the banger will have enough power to use 5th, but probably passable. The first gear will kill the deal. The 3.97 with the 4.10s gives you 16.27 overall. Anything over 10 or 11 things start to get gear bound and useless. You will never use 1st gear unless you want to pull a few stumps. I ran a few rear gear numbers and really can't find one that doesn't kill one end or the other.
I forgot to mention, we’re running 7.50/16s, so a 31” tall tire. I’ve read that stock A’s have a 3.12 first gear, and most had 3.78 or 4.10 rear gears. That would make them roughly 11 or 12 overall. Thanks for the replies! I have no experience with a banger, and I knew there was lots of experience to draw on here!
Running 3:54 in a stock A rear end with 29” tires. Engine is B with a CRAGAR head, headers, Weber 32/36 carb, electronic ignition. Car is a ‘29 CCPU weighing 2400 pounds.
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