90hp head wrecked, can I use a 140hp head?

Like the title says, I'm trying to get my motor going, got new gaskets on the starboard head/cover, cleaned out a world of crap. Went to do the left head and broke 3 1/4" bolts. In drilling them out I accidentally drilled through the head into the chamber area. I can get it welded but I've got 2 140hp heads of a spare motor I can put on...I think they're 140's I was told that but I'm sure the guy didn't really know. They are off of an early 80's alleged 140 or could be 115 bubble back power head. The bolt pattern and jacketing is the exact same as the 90 heads but the upper inside chamber is contoured slightly different with a bit smaller area. Would it be just a matter of compression? If I didn't change carbs or reeds or anything, would it affect much? Don't care about getting more hp, just want to get it together...
Thanks.

Re: 90hp head wrecked, can I use a 140hp head?

Can you post pictures of the 140 (??) heads? There are some guys here that would know what they were on sight and could tell you if they would work. I suspect that the pistons on the 90 are not a "match" for the other heads.

Re: 90hp head wrecked, can I use a 140hp head?

I'll try to get pics later, the pistons in both power heads look identical on top, there is a part number on the "140" head, it's 326502 for the port side, 326503 for the starboard. The one's from the 90 I think are 326504-port 326505-starboard, it's hard to read they're almost wore out...

Re: 90hp head wrecked, can I use a 140hp head?

We'll keep bumping this one up and see if Chinewalker or someone will answer.

Re: 90hp head wrecked, can I use a 140hp head?

Thanks.

Re: 90hp head wrecked, can I use a 140hp head?

The pistons are the same in both motors, so the heads will work. The 140 heads are a bit tighter, so replace BOTH sides with the 140 heads to keep things balanced. You'll note that the casting numbers on the head pairs are sequential. The idea is to keep a sequential matched set on the motor.

Re: 90hp head wrecked, can I use a 140hp head?

Awesome, thanks! One more note, the 140hp motor had oversized pistons/rings in...0.030". You don't do anything to the heads if you oversized the bore/pistons do you? Not sure about this.
Thanks again.

Re: 90hp head wrecked, can I use a 140hp head?

Correct, heads are not altered...