tappet adj bolt choice? advice wanted....

[AdminGuy]

I've purchased at different times two tappet adjustment bolts and nuts from two different Indian suppliers. A common problem (fustration) for me is that they are very different. Each has some pros and cons. So I'm trying to figure out the best thing to do. Busting a tappet bolt in the middle of no wheresville is not something I'd like to experience.

Both are heat treated. To what Rockwell hardness not sure.

The black set on the left seem to be anodized. The nuts are very stiff. So I was thinking these would be good on the exhaust valves which put out alot more heat/abuse, expansion/contraction. They are flat topped.

The set on the right are very close to OEM. They have slightly domed tops. Which I think is good for the pounding they will take (pounded flat) and will allow for a more accurate reading with a feeler guage. The nuts turn freely.
So intake valves I figure.

What do you think? Could use some advice here.

[indianut]

Stock was domed. Intake and exhaust.

[INLINE4NUT]

Admin,
just my 2 cents but....... if it was good enough for the factory (intake and exhust ) then it should be good enough for you and I ! Id go the way they did sometimes your better of not to second guess !!

[AdminGuy]

I understand. I think the black adj bolts would be good as they are stiff and will hold adjustment, ex valves. I guess potential problems could arise when the valve pounds itself into the top of bolt and creates a slight indent. Thus making adj a little more difficult w/ feeler guage. I've found just moving it up and down by hand (for feel of gap- my calibrated hand) gives a very accurate reading. When the top has been pounded below surface.

If pounded below surface - I'm a little concerned that valve could catch the lip and snap the adj bolt. So I'm considering grinding a dome head on each of these. Carefully leaving the heat treat in the center. What do you guys think of that?

[indianut]

All you have to do is hold it to a sanding disc with a rubber backing and spin it...or chuck it in a lathe and hold a 220 stone up to it until you get a slight dome. The factory spec is something like 22"Radius. You WILL NOT go through the heat treat! It is hard probably .050 deep.