When converting to R134 from R12I found out that there is a parallel flow
condenser

http://store.ackits.com/index.cfm?fuseaction=Parallel

that is 1/3 more efficient than the OEM   that can improve cooling.

You can get a size that is approximate (Maybe even bigger to improve
cooling) to the OEM size.  You will need to get an extension tube so both
tubes can bolt up to the stock lines.

Someone on the list also mentioned a improved evaporator replacement (do not
know source or part number).

Since most say that the R234 conversion is "OK" but not as cool as the R12,
they probably do not change the condenser and or evaporator so changing
these can bring the temps down inside.

The only question would be is how well does the compressor work using R134
vs. R12.

Robert

With slowly nonfunctioning A/C. :(