It looks like the rules would allow the 1500 since it's
a legal GT4 engine. I suspect the challenges would
be many, though. Getting competitive power starting
with the stock heads might be a big effort. I don't
have any idea where one would go to find headers,
intake manifolds, dry sump system, a machininst/
builder familiar with prepping the engine, etc. Mating
the engine to a suitable transaxle could be a challenge
as well.

--Rodger