[67Lemons]

So I have a 1968 400 with a set of #15 heads & I’m going to be replacing the camshaft, lifters, timing set, oil pump & valve springs for an 068 cam that I plan to purchase. There’s a set of #16 heads with screw in studs available for a decent price that I’m considering purchasing so that I could run a cam with a little more lift like the Crower 916 but now I’m starting to wonder if it’s really worth it in the end. The 400 that I have is an original 40k mile motor out of a B body car that runs great with no issues, my original plan is to install the 068 with a cast iron intake & quadrajet then put it into my ‘67 LeMans. For a street cruiser with a 3.23 gear & turbo 350 trans is it worth the extra cash/effort to swap the 15’s to 16’s just for screw in studs & some more lift from the cam?

[steve25]

It depends on you.
The since the 16s have screw studs they are also big valve heads and even with the 068 cam will buy you 15 more Hp and the same gain in peak TQ over running the 15s.

If the 15s are not on the motor and you wanted extra insurance against the studs pulling out you could check into getting the studs pinned.

Another consideration is if the 16s are less of a drop on due to having higher mileage then your low mileage 15?

With either head even if they are not rebuilt you want to replace the valve stem O rings so you don’t burn oil.

Both heads will provide high enough compression that octane reduction due to oil getting in the chambers could make the motor far more likely to ping or knock.

[67Lemons]

Originally Posted by steve25

It depends on you.
The since the 16s have screw studs they are also big valve heads and even with the 068 cam will buy you 15 more Hp and the same gain in peak TQ over running the 15s.

If the 15s are not on the motor and you wanted extra insurance against the studs pulling out you could check into getting the studs pinned.

Another consideration is if the 16s are less of a drop on due to having higher mileage then your low mileage 15?

With either head even if they are not rebuilt you want to replace the valve stem O rings so you don’t burn oil.

Both heads will provide high enough compression that octane reduction due to oil getting in the chambers could make the motor far more likely to ping or knock.

Actually, I forgot to mention that the heads for sale are small valve heads that were converted to screw in studs, if they were larger valve heads I’d probably already own them

[steve25]

Well then run your #15s and if you can get it done local enough and afford it get the studs pinned.

If you or a buddy have a decent drill press you can do it yourself.

[Skip Fix]

High performance 409s used pinned studs from the factory.

[HWYSTR455]

I see no reason to pin studs if you have it apart, just convert to screw in. That can actually be done on the car if you're careful. I think I still have an H-O guide for drilling somewhere, but recall some are remaking them if you dig.

Regardless of cam, springs, etc, going to studs is SOP in my opinion, never run pressed in studs.

Same with pushrod hole enlargement, SOP.


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