torque converter problems

[V8bug]

I have a 283 sbc around 9.5:1 cr with a summit 1103 cam, 214/224 .442/.465.
It has a tpi intake and megasquirt controlling fuel and ignition. I got the car to idle inbetween 900-1000rpm, any lower and it gets unstable and stalls.

when I drop the car into any gear the rpms drop to around 500rpm and the engine stumbles for about 4 seconds and dies. To get it to run in gear I either have to raise the idle to about 1200rpm (but then it makes violent clunk when shifted into gear) or I have to catch the engine before it dies and keep on the gas.

This is no way to have my car operating. I have thought about changing the cam and decided against that. The torque converter in there now is a summit
SUM-G2700 that they say has a flash stall of 1700 rpm, and a stall between 1500-1900, feels like a stocker though?
should I buy a converter with more stall? summit sells one with a flash of 2000 and a stall between 1800-2200 i think.

The car in question is a 71' vw bug with a ford 9" and 2.75 gears, can't weigh more than 2500 lbs

any help would be great!!