pretty soon when Jason gets his back-ordered hotcam kits in I will be installing one, I am wondering if I should change the head gasket at the same time. I think I have 60-70,000 miles and hate to change it unless these gaskets are prone to leak at low miles. I was hoping to double my mileage or wait until I blow them with a supercharger upgrade. I just hate to go in there and do all that work, then do it all over again because our gaskets don't hold up well. How many of you guys changed at the same time. Anyone know how much the Impala head gasket raises compression. I assume the extra compression is only worth a few ponies but every little bit counts.

 

Personally I wouldnt do it unless you have a problem already. Thats a lot of extra work if nothing is wrong right now.
Youll gain some compression with the impala gaskets but since as a rule you only gain about 3% more HP with every whole point of compression it wouldnt be worth it for that soul purpose in my opinion.

With the impala head gasket youre CR would be around 11:1

 

As far as I know my last head gasket hadn't been changed for 150k miles (had not been changed since I owned the car), it was only changed recently because of the engine rebuild. I wouldn't do it, thats way too much work for something thats not necessary, plus the only things that the two jobs have in common is intake and rocker arm removal which is easy anyway.

My vote is no, unless you think you have a leak, way too much work.

 

IMO you should change gasket every time you remove the heads... and i think a gasket change is worth .5 compression and 1.5 % HP thats 5 hp.... and IMHO i believe he would get MORE than that with 11:1...

 

I would agree, however he is not removing the heads.

 

With the miles on my car, while im getting my cam done, mind as well get some cleaned up heads and change the gaskets...cause sooner or later the gaskets will go and i'll need to tear it all apart again...

so i'd do the gaskets, but its a lot more work..

 

Not to mention, ( my 2 cents) you could replace the valve stem seals and even remove the valves and take off all the carbon deposit that has built up during the years, might get you better flow and all----just a thought. Also, you would get a feel for what it takes to do the job and later on do it on another car of yours or charge your friend to do it for them--works for me.