I have a TH350 behind my mildly cammed 350 - has been rebuilt with shift kit but still shifts early thru all gears like a stocker. Installed a B&M adjustable modulator, which should be good for 2-3 mph upward adjustment but should I ultimately be considering a governor replacement or recalibration kit? Governor is likely original to the trans but not seemingly faulty.
TCI sells a nice governor recalibration kit with weights and springs. Lighten up the weights at 1st, then fine tune with the springs.
B&M also sells a kit, part number 20248. I have used this kit twice and it did what I wanted. Both Jegg's and Summit sell them but you might not see them in their catalog, just ask the sales person on the phone.
Yup - 20248's on Summit's website too - both kits look pretty well suited for what I'd want if they work on shift points below WOT. I'm running 3.23 gears now and I think the transmission was already set up for 3.08 - it's the original mate to my '70 SP motor. Right now it shifts at just about the same points as the stock '72 I pulled from the car (which had last been rebuilt in the 80's from what I can tell).
You can put the shift a little later by adjusting the detent cable at the carburetor; also by adjusting the modulator, if you have an adjustable one.
So....do you introduce more slack into the cable to make the car shift later? You can't make the cable pull any sooner (tighter), otherwise it will prevent the throttle plates from opening completely... can you expand on this a little? I have the same problem with my TH350. Thanks.
Wide Open Throttle upshift RPM is controlled by the governor. The vacuum modulator will only give 2-3 MPH on the minimum and part throttle shifts. Forget the detent cable, it is self adjusting at the gas pedal. Buy the B&M or TCI kit and start testing until you get what you want.
I took a dremmel to the stock weights (ends and sides at the end), started conservative until I got the shift points to where I wanted them (4900-5000). It took a coulple of times to get it where i wanted. I was running a stock 100k mile 455 at the time. I took the governor apart so I would not get any filings in the sensitve parts. I did buy a kit but I only used the replacement pins that secure the weights. I cleaned everything and put it back together. I read that the governor is sensitive to dirt. Also I noticed that when I built the new motor (425-435 horse) and added the 3200 stall converter the shift points changed to 5200.. It ended up being perfect. Guess I'll soon see what the rebuilt tranny with the b&m shift kit does to the shift points...
