I posted a while back but with no response.

My question still stands.

While I was working on my heads I accidentally made a scratch that I can barely feel with my fingernail. I know this sounds minimal but I hear that even a human hair on the mating surface can mess up a seal completely. I don’t want to compromise anything here. I want this to seal this time completely.

Will copper spray do alright or what?

If you must question, I was sanding the mating surface with a big piece of finish wood and 90grit sand paper, the wood was the flattest and widest surface I could find to use for this. But I got all the surface rust off very easily. But when I did something a grit of, I think, concrete scratched it. But as I said you can barely feel it with a fingernail.

 

Just depends what type of gasket you plan on using. If it were a steel shim type and the scratch was in the right spot I might think about it.

If your that worried is there no machine shop the can re-surface your heads in your area?

 

There are many machine shops, i just dont have the money to resurface my heads.

the head gasket material i chose is composite material.

 

Are these aluminium or iron heads btw?

 

they are iron heads, 083 casting...

 

Well i've put iron heads back on that have had deep gouges in, caused by all sorts over the years, and never had a problem.
If it was alloy, it would be a definate head skim, to eliminate warpage and any "scratches".
The only time i've skimmed iron heads was to raise compression.
Using a composite gasket shouldnt give any problems at all.
Just polish it up as much as you can, and of course the block side, and all should be well.

 

Don't bother with the copper spray. install the clean grease free head and gasket on a clean grease free block.
You can do a compression test on the motor while its still on the stand to verify proper seal. I don't think you have to much to worry about.

 

I have some 416s i got used and was wondering what I can prep the gasket surface with, or should I just scrape it with blade to remove any excess gasket?? I was just wondering if I should scotch pad it on a die grinder or like sand it with a certain gritt to clean the surface?

 

On a cast iron head you can use a drill witha light wire brush attachment, a DA orbital sander with fine grit if the gaskets mainly stuck to the head, being cafreful not to concentrate in one spot. If its just a few bits left stuck, i use a paint scraper or a stanley knife blade [with gloves on !!].
Cast iron heads cant take quite a bit of abuse, as long as you dont go mental!!
I always have aluminium heads skimmed, even on old Jaguar XJ's, and they are a big alloy casting, skimming removes any gasket anyway, putting back an alloy head unskimmed is too much of a risk for me personally.