I have a domed piston 454 w/ new 502 heads- I don't know the size of the dome bc mechanic didn't tell me. Probly stock head gasket. Can I throw a 177 on it?

Consult your mechanic

I'll try that but I don't think he's on his A game for high performance motors he's more dependability type.. 2 years ago I walked into his shop and he had a short block w domed pistons w a stroker kit.. After the build continued I later asked what time of aftermarket crank was in it, long story short he's got no clue... So what's the a safe max compression w 5 pounds boost

There's a lot more to it than that. Start off by getting together everything you do know 100% for sure of in your build.

pantera232 don,t take it personal but some of the people around here that are well versed in this stuff are reconsidering giving their opinion,only to be told by people that don,t have a clue they are wrong.i,m not saying that you would do that but it has been happening lately.

Garbage In = Garbage Out

You need to give us more specifics.

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Mr Mike - you need to drop it or atleast stop bringing that up on every thread.

If your disgruntled, try posting bikini pics . Makes everyone feel good ! LOL.

mr sb,thanks for your sugestion,i am not disgruntled and i can respond as i see fit.i suggest you check to see how many posts i have said this before.i am not speaking for any one else but i am going to sit back and watch for a while,afterall nobody needs the input of a [INTERNET ENGINE EXPERT].looks like you will need to start answering more questions!i,m pretty pasionate about this stuff and i will leave it at that.

Or you find a piece of a broken drill bit somewhere in it. Used carbs that I don't know since new make me shudder.

Pantera-
If your engine started life as a 454 Mag then you have the TRW 2399 piston, it has a 13.8 cc dome. With a 088 Head (Stock 502 Head) which is supposed to be a 118 chamber (you will only know for sure if it is cc'd) you will be at 8.75 CR. I hope this helps you out.

Stroker kit? Unknown crankshaft? Unknown piston dome size ? Unknown chamber size?

I would skip the blower idea