andy, isn't your duster an automatic ? if so, what converter do you have ? TIA as always.

Sort of. I made some big changes since I put the ET in my signature. Our local track closed so I retuned the engine to run on pump gas. I went from 13:1 compression to 10.5:1 while at the same time ditching my OOTB Stealth heads for a set of TF 270s and the deep port matched intake. Cam is the same, but advanced 4 degrees at the recommendation of Bob George. The old combo would hit a wall at about 5500 rpm. The Stealth heads just wouldn't let the 512 breath past that. I have hit 7000 rpm with the new combo and it was just singing along. Not sure when I'll be taking it to the track to see what it will do. I have no doubt the car will now be in the 9s so I hope I can get one really good pass in before they kick me off the track for not having all of the "stuff" needed to run 9s legally. I'm done racing since I moved to this rural community specifically for it's race track. It's just going to be a fun street/show car now.

The top was already very smooth when I got it from you. I just hit it with some Mothers polish on the top edge. The face isn't polished, but I did hit it with gray Scotchbrite to even out the sheen.

I'm running the 295/65x15 MT SS with 3.73s. The converter is a 4200 8". There is no lack of low end torque!

10 inch street converter from Turbo Action. Part number is 17805ST-17022. You would have to call them to confirm exactly what it is and if it would work for you. Paul described it to me as the tightest 10 inch converter they build for Pro Street type cars. It is the only converter I've run in my Duster so I don't have any other data points. This one seems to work just like Paul told me it would. It is loose enough that the car idles down and it doesn't push against the brake at stop lights, but it only slips about 4 or 5% at freeway speeds. I don't know how much it will slip in high gear at the track since I haven't made any passes yet. It slips a lot when you go WOT from a standing start but it starts to catch up as you go down the road. I just don't know how long it has to go before it catches up at WOT in high gear.

I like that story. Moved to a rural area just for the track and now you're done racing. Funny how stuff works out sometimes. I understand completely.

Andy my plan is a Dana from dr diff. 3.90 or 3.91 gear is available.

That looks like the Tucson ,AZ area, is it?

I use to have both types of M/T ET Street and ET Street Radials of the same size, 325x60x15 on the radials, the radials didn't hook worth a hoot on the street, the bias ply where way better on the street
The radials where quicker and faster at a decent hooking track, not good at all on any semi slippery surface like most streets around here
As far as rear gear ratio I tried 3.73, 3.91, 4.10 and 4.30 in my old pump gas Duster, almost no noticeable differences other than spending more time in high gear at 1/4 tracks with the 4.10 and 4.30
That motor started off as a 511 C.I. with 9.25 to 1 compression with big valve slightly ported 906 heads and ended up at 517 CI. by increasing the stroke from 4.25 with -.026 piston deck height to zero deck height with a 4.300 stroke crankshaft, which increase the compression ratio to 10.29 to 1
I really like that car, it far exceeded my expectations 9.993 at 134.7 MPH cork up with the full 3.0 exhaust system and air cleaner weighing 3450 Lbs. with me in it

I'm close to Wickenburg, AZ.

Boy was I wrong
I caught a bus in Wickenburg to go visit my cousins who lived in North Las Vegas at that time, circa 1960. I lived in Blythe back then
I drove through Wickenburg from up here in Oregon down through Kingman down to Tucson in 2013 to pick up my current S/P car, lots of change to the entire area since 1960
I raced at Speed World in the mid 1990s also back when i lived in Hesperia, CA To bad it is still closed now

Speedworld had just celebrated it's 50th anniversary 2 years before it was shut down So depressing.