409 Deck Surface Question, have nick under head gasket ring

[hrlykngt]

May be over thinking this. I probably wouldn’t have given it a second thought on one of my old small block builds back when I was racing years ago . I got my deck of the block cleaned up. I used a nylon brush wheel to clean without removing any material. This block was decked before I got it. I have checked with straight edge and it is perfectly flat. I have a spot on #7 cylinder that has a small nick maybe .010 deep I think I may have hit it with shaft of grinder when I was cleaning up. Do you think it will be an issue. If there was some one local I might try to get decked again but as I said has been cut before. I’m not sure how much. Walden did it back in 2009 before I ever got motor. The motor never got built as the owner passed away. It sat till I bought from guy who bought from widow. Here’s some pictures I put gasket on and marked to show where ring is. My pistons are 10.5 Ross I’m assuming block is 0 deck or close to as all numbers are gone. I have Felpro Permatorque gaskets. Solid copper might be an option if you think I might have issues with. Just not sure how to proceed. Gonna shoot for about.040 quench from what I’ve read on here. This will be a hot rod toy, ride to town and such on weekends maybe take to drag strip on occasionally.

 

[1958 delivery]

Doesn't go anywhere so I think it's ok.

 

[Ishiftem]

If it falls under the ring, I would have it cleaned up. Mock it up and see what the piston to deck is now. Even at zero and you deck it, you could deck it a little extra and go with the next thicker gasket.

 

[SSpev]

Would not want to leave it under the fire ring. I'd put spot of weld on it with a mig then file it flat.

 

[Murphdog]

If the damage goes under the combustion chamber armor you need to surface it. Like Dan said, mock it up and measure. I try to get the top of the head gasket 9.830ish from the center of the crank. In my opinion that is where GM had it. Reason for this is manifold fitment. But this hinges on piston height also. You want .040/.045 quench. Your 8007 Fel Pro is .042/.045ish thick compressed (you could call them) and will require about .025 removed to get to 9.830ish. Best head gaskets are .044 & .054 compressed. You can always go Cometic if you need thicker.
Jeff

 

[hrlykngt]

What are the best head gaskets to run with the aluminum heads, I have heard composite? From what I have been searching on here lots of folks had problems with Felpro 8007's.

 

[Murphdog]

What are the best head gaskets to run with the aluminum heads, I have heard composite? From what I have been searching on here lots of folks had problems with Felpro 8007's.

Personally, I can't say as I have a preference. You essentially have 4 choices, Fel-Pro, Best, Cometic and if you can find them, original GM steel shim. Original GM has 348 & 409 gaskets. Different bores.
Jeff

 

[Don Jacks]

I;'d go with Cometic.

 

[hrlykngt]

Its looking like Cometic.
I went to their website and they show gaskets from .020 all the way to .080 in several increments, this will help alot if I have to get this deck cut again, it has been cut already I know since numbers are gone. What are the 4.437 Gaskets for, that would be a .125 over bore? I wonder if I could use one of those without decking block or should I stay with the 4.375 Bore, Mine is .060 over so would be this one. Thats .062 , half of that would be .031 per side. not sure if that would clean it up anyways tho.

Here are the links if anyone is interested:

Chevrolet Gen-1 Big Block Chevy 409 - 409CI/6.7L V8 Gaskets

Cometic Gasket supplies hi-performance gaskets for a variety of motorsports markets: ATV, Drag Race, Domestic Automotive, Harley-Davidson®, MX/Dirt, Off-Road, PWC, Road Race, Snowmobile, Sport Compact and Street.

www.cometic.com

Chevrolet Gen-1 Big Block Chevy 409 - 409CI/6.7L V8 Gaskets

Cometic Gasket supplies hi-performance gaskets for a variety of motorsports markets: ATV, Drag Race, Domestic Automotive, Harley-Davidson®, MX/Dirt, Off-Road, PWC, Road Race, Snowmobile, Sport Compact and Street.

www.cometic.com

 

[Murphdog]

Its looking like Cometic.
I went to their website and they show gaskets from .020 all the way to .070 in several increments, this will help alot if I have to get this deck cut again, it has been cut already I know since numbers are gone.

Here are the links if anyone is interested:

Chevrolet Gen-1 Big Block Chevy 409 - 409CI/6.7L V8 Gaskets

Cometic Gasket supplies hi-performance gaskets for a variety of motorsports markets: ATV, Drag Race, Domestic Automotive, Harley-Davidson®, MX/Dirt, Off-Road, PWC, Road Race, Snowmobile, Sport Compact and Street.

www.cometic.com

Chevrolet Gen-1 Big Block Chevy 409 - 409CI/6.7L V8 Gaskets

Cometic Gasket supplies hi-performance gaskets for a variety of motorsports markets: ATV, Drag Race, Domestic Automotive, Harley-Davidson®, MX/Dirt, Off-Road, PWC, Road Race, Snowmobile, Sport Compact and Street.

www.cometic.com

You need to either mock it up and measure or do some good measuring. Mock up is probably best. You may have enough left on the deck to just cut and use your Fel-Pro's. The Best gasket is available in .054. Cometics are fine, just more expensive. You need to figure out where you need to be, before you try to get there.
Jeff

 

[Ishiftem]

Either type gasket will be fine.