I've been doing research all day and I think I want to change the tranny to a COAN Street Performance THM-350 can anybody offer any tips on what kind of modification I would have to do to my car in order to succed in this conversion from two to three speed? I've heard that all I'll need is a cable of some sort and I'll have to change my speedometer settings or something to that effect... I also wanted to know if this is a good choice of conversion for my small block 300? The ST300 will become my new boat anchor ha ha stupid piece of crap hopefully in a month or so after the engine overhaul new tranny and a carb rebuild I'll be smooth riding in my Special :3gears:
Deffinitely a good choice. Will bolt right in. The only issue is that you will have to create some method of activating the kickdown cable. (300 uses an electric kickdown, 350 uses a cable) No change to the speedo needed
I don't know enough about the finer points to mount a defense of the ST300, but here are a few things to think about. As I understand it, the ST300 IS based on the powerglide, which is still considered a fine racing trans when set up correctly, with aftermarket gears, etc. The ST300 was designed as a switch-pitch, unlike all of the cobbled up S/P set-ups that are all the rage nowadays. Sure, the 200 series trans has overdrive, but look at the work you have to do to one to keep it alive under racing conditions. For one thing, you HAVE to start with a 200 from a GN or a Hurst/Olds, and they are going for steep prices as cores. There are some bolt-on o/d setups available that I hear are quite good, and only require a driveshaft mod(the Flint Flyer had one of these, and it was pretty trick). If I was going to invest money in my trans, I'd take my ST300 to a racer who specializes in powerglides and put in a modern S/P converter. Then I'd put in a bolt-on O/D setup with a resized shaft. I'd probably end up saving money and have a numbers matching setup that would run with the rest. I don't know what weight savings I'd get with the 200, though it's all bracket racing anyway, so consistency is where you win, and not the extra .020 seconds at the finish line.... Any thoughts, comments or rude gestures? Dan
A 300 has no parts that interchange with powerglide that I know of . The most useful thing on a 300 is the converter and it fits a 350 or 400 turbo and works well . Ed
