Beginner Road Track Racing: Feedback on Engine Options Wanted

What class is this for ?
What are the rules ?
Do you want to be competitive ?
Win seasons or the odd race or just have fun ?
Handing is gonna matter more then the engine.

You kind of have to know the rules inside and out to find any advantages, when I wanted to do Time Attack the rules seemed to put more value on stock hp ratings of the engine than modifications.
So I figured modifying the lowest rated V8 engine would of gave me the best advantage why my name is 273, cause it was gonna be either based on 2 bbl 273 or a 1980 (i think) 318 cause it was the lowest rated 318, would of been whatever engine they valued less but then I realized I'm not well off and this type of racing is above my pay grade among other things.
I'm not planning on class racing or focusing on competition aside from pushing myself. I joined a regional club and will be competing against those cars when we rent the track. When not running on those days, I will run at open track days to have fun and learn. The goal is to have a classic Mopar on the track, learn to drive it, make improvements as I go, and have fun.