i know you usually change design when you find something better, but why did the tpi corvettes keep the in cap coil set up when the later thirdgen tpi cars went to an external coil?

 

Maybe one of the members who isn't "we tah did" is best left to address such a serious issue .

 

as the name states, U R we tah did

 

Small cap:

Advantages:
Easy to change the coil to a performance coil.
Looks neater and gives more clearence to firewall.

Disadvantages:
Must find a location to mount external coil (duh)
Terminal spacing closer, more chance of carbon tracking causing misfire to wrong plug.

Big cap:
Advantages:
Mounts easier
Wide terminal spacing

Dis:
Coil selections limited and real high output coils can heat the carbon contact inside and melt the cap.
Increases temperatures inside the cap, not really a great thing for the module to put up with.

If you want to swap one for the other, you will need to cut off the 4 pin connector and change it over, they arn't a direct swap. And hack up the coil connectors and reroute the tach wire.

Cam/Frbds came with the coil in cap upto 87