My "new" '74 Duster- or why I need a project like a hole in the head

goldduster318 said
Glad it's done. I like how in general we made the same thing in different ways (my conversion for others reference is https://www.forabodiesonly.com/mopar/threads/t56-magnum-conversion.416558 ) My kit came with the sleeves for anti-crush and also I didn't cut anything off the transmission, my tunnel is slightly wider, I can pretty much install every bellhousing bolt from the bottom with some minor engine tilting.

My transmission isn't an XL, its the same case as yours, just the TUET-16885 which is 2.97:1 1st and 0.63 OD. I have driven mine for a couple tanks and I'm getting 15 mpg on short trips so its about 1.5 better than no OD. The Cruising factor is incredible though. Now that its broken it it shifts like butter. No kidding it's incredible, I doubt you could make a better upgrade to one of these cars. In my case with the 25.6" dia tires and the 3.23 is 1900 rpm at 70, mine pulls it awesome.

The other thing is this transmission holds 700 lb-ft of torque so you will have to try to break it.

In my case, good to know about the corvette hydraulic throwout bearing, I'm not a super huge fan of the aftermarket shimmed ones.

Curious about the choice of Syncromesh fluid, considering the giant Dexron III only sticker on the side

Good to know! Yeah I had a fairly early version of the crossmember, there were some changes made along the way and even though you did the swap before I did I had the crossmember before that. Drawback of collecting parts over a few years I guess.

Shifting the T56 is so much nicer than the 833. Even though the 833 I was running was fully rebuilt by Passon it's just not the same as a new transmission. I think my biggest issue is dialing back the effort for the shifts, the T56 shifts so easily and the long B body shift handle is a bit much, it's easy to overdo it. The 340 in my Duster has always been a little light below 2,200. Which honestly makes sense to me, the cam in it is rated for 2,200 to 6,400. It's not like it's a total dog, but the whole package just works so much better above 2,200 it just makes sense to drive it there. It pulls like a monster from 3k up. But it's a hydraulic flat tappet off the shelf cam, I'm sure if I went to a roller I could pick up some more bottom end.

I never liked the aftermarket throwout bearing deal, the shims and everything, the generic application, etc. And once I went with the B&B clutch plate I was pretty much committed to not running one because of clearance needed on the fingers. The C5 throwout seems to be working great.

As far as the syncromesh goes, that was straight from Tremec, and it's right in the description- "Chevrolet Performance Synchromesh transmission fluid is designed for GM manual transmissions and is the recommended lubricant for all Tremec brand manual transmissions". It is after all supposed to be an LS1 transmission.