I have 540's and was wondering if I can just drop blowers on them and be off and running?????? Here are some specs on the motors: they started as 502's then bored/stroked to 540's w/ 4.25 cranks, 9.5/1 compression w/ iron heads.......I have heuber trannys and #4's so im not really worried about blowin drives....

I,m no expert by any means but 9.5 comp seems alittle high for a blower motor. probaly would change the cams also.I'm sure someone with more knowledge will chime in. good luck

I would not put blowers on that combination. A hole in a piston or a cracked head are just around the corner.

i can run thicker head gaskets to lower compression a little right????

If it was a 502, I doubt that it was a bowtie block. Compression is way too high. I would forget the blower and enjoy the boat. Compression needs to be 7.5-8.0 to 1. I'll bet the internals are not strong enough to handle the blower either.

ok i guess ill have to get all of the engine specs before i can even think about it....ive seen guys on here saying they took their 540's and put blowers on them without any further mods

The compression is to high with the cast iron heads. I have put Whipples on 598's that were over 10:1, but they had alum. heads. If you ditch the cast iron heads, you could absolutely put a blower on it.
I would not just install a thicker head gasket to lower compression. You will lose your quench and that will make the engine more susceptable to detonation. There is no problem with the 502 block. What type of crank, rods and pistons? They are the biggest concern for reliability, not the block. I have made a 1000+ hp with a 502 block, so no worries there.
What blower do you have in mind? That will determine what comp. ratio would be ideal.
Eddie

thanks eddie, im really not set on running a particular blower by any means, but I am not planning on running high boost, maybe 4-5lbs.....

check out pro-chargers marine systems tought a 40 % power increase. yes you will have to improve fuel delivery and lower compression. they shouls have all the info as they have sold piles of them.
Bosco

And most have been removed for something that works.