Rear opinions--all over the place
Bill- You will get opinions, from professionals and non, varying widely regarding your choice of a Dana 36 or 44. There is no question that the 44 is larger and a bit stronger. 'Pros' told me: 1) neither is strong enough, 2) either is strong enough, 3) my 36 broke due to lack of care, indicated by the color of the inner case, 4) the color is normal, and the care was just fine. Consistant opinion was TOTALLY lacking, from guys who do these for a living!
Later C4s, (not sure which year) with manual trannys, came with the 44. 44s can be 1) hard to find, or 2) expensive, or both. You might contact
Vettemasterstom@aol.com if you decide to shop. They wrote me, after my new diffy was underway, saying they get them all the time and price them at $1700-2000, used. Tracy Performance sells rebuilt 44s for $4200+.
My experienced, well-reputed diffy shop, who has done fine work for me before, did some checking. Jerry, at Unitrax in Anaheim spent quite a LOT of time on it. They have built diffys for many Vettes, Vipers and all sorts of vehicles, including trucks and motorhomes, and have done it for decades. Jerry speaks the truth, not hype.
I opted for a cryogenically treated, later design Dana 36, as I could not find a reasonably priced 44. The case
and the internals were cold-treated for strength; the case, as it is part of the rear suspension and my early-design case had cracked. I changed from a 3.73, contacting on 1 tooth at a time, to a 3.54, with 2, plus a deeper contact area. It differs, depending on the manufacturer. Jerry said I can break this, but could break a 44 as well. With either choice, I would have re-done and hardened the components. I chose Lucas gear lube; synthetic for its better high temperature characteristics, as the exhaust runs right under the diffy. Jerry claims
non-synthetic lubes better for 'normal' applications.
The changeover to a 44 is described in other threads. In short, you can redrill the rear holes or buy the shorter C-beam. You will need a Dana 44 rear cover (integral C4 crossmember). I believe the rest of your parts will fit.
I am accumulating miles on this 36 now and put over 500 lb.ft. of torque to this Dana 36. My BFGs spin very readily,
anytime in 1st, which I prefer to breaking driveline parts. I don't sidestep the clutch and generally treat my machies fairly well (not to say totally pampered). As the old and hard BFGs vaporize, I will seek better traction.
