subframe connectors

i've seen a lot of rave about subframe connectors so i thought i would give them a shot, but can't find any for a convertible. What's different about the chassis on the rag top model. I know they tend to beef them up, because my 94 TA convertible weighs more than my buddies 96 TA coupe. any help on the connectors would be great. Another question, if i put a 160 thermostat in the car will i need to have the pcm upgraded?