Determing Stall speed and shift points

[SUX2BU99]

I have a stock TH350 in my truck (85 Shorty fleet, mild 350, 2wd) but has a shift kit in it. It was rebuit at some point and I think a new TC put in it. I don't know the stall of it. But to try and determine it, if I do a brakestand, the tires will (reluctantly) start to turn at about 17-1800 rpm. Would this be my approximate stall speed?

And the shifting of my tranny kinda sucks. It shifts at best at 4000 rpm when cold/cool. When warm, this can drop to like 3700 rpm. It also won't downshift if over 2000 rpm at WOT. What can I adjust? Detailed instructions please

[VileZambonie]

first you really don't need to know your stall speed for any other practical purposes other than engine building but if your curiousity needs to be satisfied you can do the stall speed test just realize this can cause some serious damage if you're not careful and don't keep repeating the test. Hook up a tachometer. If your brakes won't hold your truck than I suggest cleaning and adjusting your brakes - set the brakes and hold your foot firmly on the pedal. Accelerate in gear to wide open throttle and record your max engine RPM - there's your stall speed. If your tires are spinning the test is void.



Tune it up - change the fluid and filter - replace the modulator with an adjustable vacuum diaphragm. Tighten up one click at a time on your TV cable until it shifts where you want it. The vacuum modulator causes the modulator pressure to respond to engine load. When engine load is high it can delay an upshift or force a downshift (example passing manuever).

[SUX2BU99]

Thanks for the info. I do have a tach and engine speed will pretty much stay at about 1500 rpm, unless I ease up a little on the brakes and the tires start to turn slowly at 1700. I'll estimate my stall is somewhere between there. Yeah I don't do very many brakestands since they are quite hard on the driveline especially if it's difficult for it to do one. I do want to know since I am interested in replacing my cam, intake and heads as discussed in other threads and as you know, some powerbands do not coincide well with a low stall.