The modulator valve on the back of a 350 is what controls the shifts....right. Inside the nipple is a screw that can be turned in but not sure which way is higher or lower. If its bad then it could be the problem. I checked on one for a guy last week and one of them is about 40-45 bucks at the discount store.
I'm watching to see what others think....because I think I may have the same problem but I just can't get mine up to speed on my street.....will be on the road Feb.
Boyd, I tend to agree with you!
