Head casting numbers

[Jeff K2]

I am building a mongrel, by any standard.

I have heads that are numbered 410 and 300, both appear to be F heads.

Does anyone know what these numbers mean?

Thanks,
Jeff

 

[dirtdigger]

410 I know was on 78ish f heads. 300 earlier? Not sure. What do you need to know about the heads?

 

[Jeff K2]

Thanks Dirtdigger,

My curiosity got the better of me as to which might be better or one to stay away from. One of the 410 heads is in pristine condidtion and has not been fly cut as in the one photo I posted. I think I will use it as my first trial. I have found other pistons that are very close to the weight of the stock pistons, but they are at 64.5 mm. As I recall, that should yield about 814 cc, close enough for the first stab at a hot rod motor. Too much inventory...

The head I took off the K2 has RC Eng stamped into it. It appears to be ported, but I have not spent the time to see what was done. Do these have a good history?

Jeff

 

[dirtdigger]

RC Engineering was THE place for 750 stuff in the 70's. I have dealt with there stuff before and have used some too. If you want to sell that RC head at sometime I may be interested in it. 64.5 should get you are 823. These smaller big bore motors can be made to run really well, most of the power possibility is in the cylinder heads as the stock 750 head is pretty poor at flowing and really poor at flowing for big bore stuff.