I’m looking at what class now. I sent the wrong link before. Try this one https://dk1xgl0d43mu1.cloudfront.ne...666#page69
I think you’re in the Modified category since you turboed your 3.8. How much power are you pushing and which SCCA region are you gonna run with?
If this is your first autocross you could run novice or Seat Time Only and ask around guys there what class they think if you’re really not sure.