question about chevy big block

[Clayton1169]

I have a 454 in my camaro searched the engine code and it come up 70's- early 80's 454 I was wondering is there a way to determine weather its a 2 bolt or 4 main without removing the oil pan I read some were that you can go by the number of npt fitting location on the oil filter housing but not sure if this is some old wise tale any info would be great thanks

[1969CamaroRS]

Should be a casting number on the block, usually if you can get that casting # that will tell you if its 2 or 4 bolt mains.