Sounds a good spec. 285 is a great all rounder.
Yeah AFRs are absolutely crucial with these cars. Get it right and you'll have a fast and reliable car, get it wrong and things quickly go pear shaped.
Ok sounds good just a heads up if you have never played around with the carb before they can be tricky to set up properly and require lots of trial and error.
As long as you take some jets with you and micro drill bits you should be fine. Low to mid 12s afr is good however the carb can be a bit crude at times.
Look forward to seeing how you get on
Cheers, tbh I'm going to use a guy who originally tuned the boost level. I would do it myself but to be honest, experience is key which I do not have on carb tuning.