Whats the difference between 348 and 348 challenge gearbox

What the difference between 348 gearbox and a 348 challenge gearbox

 

nothing. Some did run the lower ratio of the mondial-T box for better acceleration. Some also drilled some holes for an external oil cooler but there was no "challenge" box. There was the challenge ECU which was the last version of the spyder ecus that allowed another 100 rpms before the rev limit kicked in. Mapping of that ecu was either the same of mildly different at wide open throttle.

 

Both are still string operated

 

wow thank for the info. I own a 91 348 TB. I just discovered that the previous owner replaced the my gearbox with a challenge after blowing the original one up.

 

It was my understanding that the challenge cars used the SS/spider gearbox that had a taller 1st gear. Am I wrong?

 

Challenge cars could use any stock gearbox. There are only 2 ratios 25/27 and 25/29. 26/27 was replaced and exhausted.