I've rebuilt the 455 in my 1972 GS, with mildly ported Stage 1 heads, TA-212 cam, 9.2:1 compression. I put it back together with the rebuilt TH-400 and stock converter. It could use just a little bit more stall speed, to idle a bit better and to get moving a bit better. I really don't like loose converters but I think this car could use just a bit more. I have the converter out of my 1969 Buick that came originally with the 2-spd trans (ST-300 I think, it is not a switch-pitch). I have heard that the 2-spd converter was a little looser than the stock TH350 and TH400 converters. Would it be worth trying this converter? Or should I go straight to the aftermarket? Thanks very much Karl Koenigstein BFGoodrich Racing
ST-300 fixed pitch converters were 12" as opposed to the ST-400 which were 13". Smaller converter will stall higher. How much higher, don't know, but I think it's approximately 500 RPM/inch. It's worth a try as long as the converter is good and is not contaminated with bad fluid. Maybe you could have it flushed just to be on the safe side. o No:
