This is the approach I would take. Find a "999" transmission, it's the later 904 with a lower gear set. Typically found in late 70s cordobas and such, often with a 2 barrel 360. Run a 3.23ish rear gear, and get a converter built to suit
Keep searching. Guys buy stuff when they come in to money then never use it. I bought a brand new complete T56 magnum, bellhousing, and clutch for an LS swap for $3500. Sold the LS bellhousing and $1300 centerforce clutch for $1500. Bought the mopar QuickTime bell, and a McLeod RXT clutch for about the same cost. Stuff like that comes up often, but you gotta be ready to jump on it because it doesn’t last long.
I remember reading about the 999 when I was trying to figure what transmission is in my car. What stall speed would you recommend?
I'm not a torque converter expert by any means, but if you go this route, I'd call a reputable converter builder and have them spec it out. Your combo is relatively mild, but with a custom converter and a low gear 999, it would be impressive, and stronger out of the hole than it is now, plus cruise at highway speeds way easier. Probably the most economical swap also.
I've seen deals on TKX's and TR56's and thought about going that route.
Thanks for letting me know.
For my 2004R and later 4L60 swap, I had to trim the Torsion Bar crossover and capped that area with steel plate. I reinforced the remaining part of the crossover that curves around the tunnel portion with a 1/4" steel strap that welded to the floor.
I'll never forget what Rick Ehrenberg said about it. Push a button, and Bingo, overdrive.
I ordered my T56 Magnum swap kit from Silver Sport. Was a great kit worked well for me. Took me a few years to decide which manual transmission to swap in. In the end the T56 won out due to its gear ratios.
There is one option to connect one to a big block. I’ve never used it, but do you not like it for some reason?
I sure hope Lonnie built you that 4l60. Those things are time bombs behind any kind of power. And I know you’re stepping power up pretty big right?
Yes, good point. They are not so good in the stock form, so I looked around and went with Performabuilt's transmission with the 6 planetary higher first hear instead of the 3.07 factory gearset. Performabuilt goes through them and addresses the rest of the weak points in the 4L60 have all been upgraded with aftermarket solutions as well. They essentially build it as a beefed up 4L75E with upgraded internals including both shafts, clutches and lots of other hard parts.. That unit has a much better power handling and durability reputation than it's little brother the 4L60.
I had heard the input shafts are different. I think the gears on the end are different, too. I know the R154 input shaft will not work in AX15 because of the difference in tooth count.
Interesting, I'll have to check it out. And of course, any time I get in a situation that I need some odd ball specialty parts they have to come from Australia or New Zealand at an astronomical shipping rate. The close ratio gear set for an AX15 is from New Zealand.
That does look like a nice fit.
The T56 is another contender I've thought about because of the gearing. They come up for sale occasionally for not too much.
There are two different gear ratio T56s. One is wide ratio and other is close ratio. Tremec has the gear ratios on their web site. I have the close ratio version with the 2.6 first gear.
I would think the close ratio version is more what I'm after.
There's a couple, neither is awesome.
One issue I ran into is Silver Sport sent me a cast aluminum bell housing which was excessively large which made it harder to modify trans tunnel. So I sold it to a member here and bought a Quick Time Bell housing which is much smaller easier to modify tunnel to fit. But Quick Time around twice as much as the cast bell housing. In the end all the time all the money its worth it in a big way.
I wouldn't think a cast aluminum bellhousing would be that bigger than the steel QuickTime. That might be a deal breaker because my car has factory air conditioning and the evaporator housing is touching the transmission tunnel above the bellhousing.
