chevyart

put new carb on my 355 sbc(car normally runs 11.00(aprox) with old carb(aprox 700 cfms)(new carb is 750 with proform center section). first pass and the car seemed to respond and rev up better than ever before and i figured a 11.80 to 10.90 pass in the 1/4. got my slip and couldnt believe it (11.34) car dideverything right and the 60foottime was poor, but not a factor in the ET. mph was right for the Et, but w ETwas just not low enough. next pass i had the same 60 ft. and out a little in low gear(its a glide) i felt a little something like a miss or rumble or something and comlpeted the pass and ran a slower 11.47. now i am reall confused. car didnt seem to do anything wrong, but just didnt feel as good as the first run. Now here is the real problem i am looking into. 3rd pass i got the same 60 foot as the oither runs and this time when i shifted(seemed to take a little longere to hit the shift point(7500 rpms) it hit hard into the shift, but them seemed to pause for a littlle while at around 6000 rpms and started to go up (very slowly ) to the 7600 rpms that i go through the traps at.. there was no misses in the engine and it did reach the high rpms going through the traps. car has never reacted like this before. it is a good 8 inch dynamic converter(5500 stall speen) but it has been in the car for 15 years and has only about 70 passes on it. could this be the converter going BAD.. CAR DOES NOT MISS OR POP, SO I DONT THINK IT IS AN ENGINE PART. only other thing i was thinking about (and i dont think it could happen) is that in the new carb i rebuilt i put in a 3.5 power valve in front so the car would not load up in pits. is it possible that this valv is not opening at higher prms and shift points. reason i think not is that it ran so good on the first pass and decent on the second pass. i am not knowledgeable about converters so i really need some good advice and opinions as to what my problem might be thanks art