I went and picked up my freshly machined and assembled shortblock from Mark R.'s place on Saturday. I need to select a head gasket out of all the ones available.
Any suggestions on which one I should get? FelPro? MrGasket? Mahle? Cometic? I plan to have it all assembled by the 29th and will take it back over to Mark's to make some pulls on his dyno.

 

I run Cometics

 

I just reassembled my 455 with FelPro gaskets.

 

Just curious, why didn't you ask Mark R. when you picked up your short block?

 

I’m going to text him and ask, but maybe he’ll see this post. Just wanted to see what others are using.

 

x2, they are great.

 

Looks like I am gonna go with the FelPro 1155. The block was decked, but the heads haven't been cleaned up. The FelPros are more forgiving in that respect.
Thoughts?

 

It was the opposite for me. I had the heads machined but just cleaned the deck. The gaskets worked great.

 

Tough call. It's all about where the compression ends up for me.... I don't know your end goal. 🤷‍♂️

 

My first choice for an iron headed build are Mr Gasket 5788g’s.
But if you want to use the Fel pros, that’s fine too.

 

I could get the Mr Gasket ones instead.

 

Why are the heads not being milled straight? After going through the expense of machining the short block that would be a short cut that I would not take. Any thoughts on this from the pro engine builders here have to say?

 

Because this engine had been done both on the heads side and the deck after which it had about 3-4 hours of runtime. Then got over revved and spun a coupla rod bearings. I brought it to Mark to redo the shortblock. The deck was cut again to get close to 0 deck with the new rods and pistons. There really wasn’t a need to cut the heads again. However, after going out into the garage and looking at the heads again, apparently, I missed the fact that the gasket mating surfaces have had either a cleanup pass or they are just that clean. Maybe I should go with the Cometics

 

Or you can do the Mahle 55047’s as well.

 

Ok, so it really comes down to compressed thickness desires and price since all else seems equal with fresh surfaces. And, lastly, install dry? Or use this: https://www.permatex.com/products/ga...sealant-12-oz/
I've always installed dry with FelPros and never had an issue. I definitely don't want any issues with this one.

 

I installed those FelPro head gaskets with the Permatex spray.

 

Everything on the heads is straight. All that was checked when they were done.
Deck was done to 10.615”, which puts the piston .005-.007 in the hole.
And I’d install the FelPro, Mr Gasket or Cometic/Mahle dry.

 

Cometics (or any MLS gasket) have a surface finish requirement - 50 RA or finer. Smooth finish with no mill marks. Just make sure the machine work was done with that in mind if you go that route. I've never found a reason to use sealers on head gaskets when everything is machined flat, and you aren't doing something crazy like trying to re-use a gasket.

 

Ah screw it. Mr Gasket it is.
Thanks for everyone's input!

 

I use comet they are awesome