I have a 305 HO longblock with a tpi induction on it. Would a emmisions legal crane power max cam designed for a 305 HO work on this?

Does anybody got an idea?

Sure, why not?
Just make sure you get the right kinda cam for the engine, whether its roller or flat tappet. I dont know what the engine you have in there now is.

I had the stock 305 tpi. It isnt a roller cam so i know that will match up. I just wasnt sure if the cam would be too big.

What are the specs on it?

The lift is .423"/.446" and the duration is 264/274.

That will work fine. Those are the 'advertised' specs, the .050 specs are 204/214 (more useful numbers to me )
I had a similar cam, same duration but less lift on my 86 TA. Car ran pretty good with it, if I had messed with the car more and got it to hook up (lowering does not help traction at all) it would have run 14's at the track easy. The ecm got along with it ok, but tuning will help if/when you get around to it.

that cam should be ok with tpi. the zz4 cam works with tpi and it has 209/221 duration i believe. if its not that its real close. so no your not too big.