Hang on...so you're not saying that some 64 401s and 425s got the TH400 and some got the ST400. You're saying that some Super Turbine (ST) 400s that are labelled and identified as ST400s didn't have the dual speed converter so that even if it says ST400 on the ID tag it's not a Switch Pitch? That's a worry. Because I would have bought any identified ST400 fully expecting to get the variable stator version. Do these non SP transmissions you have there identify themselves (on the id tag) as ST400s? Or just TH400s with a Nail' bolt pattern?
They say Super Turbine on them, that's why you have to look for the dual prongs on the side electrical connector and/or identify them via the pan. I pick them up wether they are Switch Pitch or not.
Wow, that's amazing and something I have never heard of or read before in all my research on the ST400s I've owned and bought. I wonder why they bothered to label them as ST400s when they are just standard TH400s? If someone sold me a ST400 I'd expect it to have Super Turbine guts and if it didn't I'd expect a refund. Thanks for the warning. Do you know if there's something else that would make them different than a standard TH400 inside?
They precede the TH400, they are what became the TH400 for the rest of GM. Cadillac and Buick got them before anyone else. The 64's have a different valve body, one year only. Other than that they are pretty much early TH400 inside. Because of this people tend to favor the 65-66 ones.
Aaaah, got it. I hope this thread has helped others as well and Langy sorry if we hijacked your thread. It was kind of relevant to your ID question.
Note: appoligies for straying this thread further, but it's very informative and hence just want to further identify a point, can Cad trans similarly be adapted? Ok, so how much carry-over items/design are there with the Cad trans, reson being that my brother has a spare T400 from a 65 Cad(hanging of a 65 429), and a 59 401, having read numerous times about the variance in the Crank between early and later 401's curious to see what's involved to identify if it might be a comparitive solution, or stick with finding the 63-65 T400 to suit the 401 etc. Cheers, Drewfus
Internally the Caddy trans is the same, but the bellhousing doesn't fit. The 59 is also a dynaflow engine, you're gonna need to enlarge the hole on the flexplate and get a bushing for the crank end to use a ST400 on it as well.
You guys ever heard of putting 401 heads on 322? I have a 322 with 6 x2's with old E2 Isky cam this is in a 1960 style dragster, called "Nut Cacker" It will smoke the tires a 100 feet now ,so has lots of torque , but always looking for more.I was looking to a bigger cam, but feel limited by the small 322 head's. thanks
I'm not sure if a 401 head will fit on a 322. I know they interchange with the 364 (http://www.buicks.net/shop/reference/nailhead_interchange.html). I'd also like to put out there that it's the small ports in the 322 heads that are giving you all that torque. For a dragster that is having trouble hooking up you are wise to seek less torque and more horsepower. Of course, once you've got traction it's back to wanting more torque again.
They fit, but I know there are some things that need to be looked at in doing so. The 364/401/425 are pretty much the same. You could pick up the 364 heads much cheaper since people don't know. DO NOT attempt to put hardened seats in them under any circumstances, they DO NOT need them.
A couple years ago, I picked up a '56 322 that had a pair of '60 401 heads on it. It also had an Iskenderian roller cam and had been bored .125, so I assume they were going for the ultimate mill as well.
Finally managed to confirm the numbers on my 401 on the bellhousing is GM1185484 on the strip in front of valley cover i have 6F1045161 with 4FI35761 upside down, I think i have a 59-60 401 ???
Langy, The 4F would be a 59 401. What does the Dynaflow have on the tailshaft, a spline and seal or a half round-style adapter? The 59's used torque tube style driveline and I believe 61 and up use an open driveshaft. Tim