Head Question

[JMSII]

Ok, I only have experience with bridged rockers.

I recently came into a set of 3216090 heads. Can you just bolt on harland-sharp or any other brand of roller tip rockers on the stock studs or do the studs need to be changed? What about pushrod length - any different?

Also, is the stock ratio on the rockers 1/5 or 1/6?

Thanks!

[jeepsr4ever]

The studs need to be changed only if you use ford small block type rollers (same length and size as the AMC counterpart without the bottom chamfer). So yes you can bolt on a set of rollers made by many of the popular companies for AMC V8's just make sure you do it by the book ;)

[fifesjeep]

I agree with Jeepsr4ever... If you go with a BIG cam with sick spring pressures then you should go with the larger studs... The cost of machining the bosses, drilling/tapping etc is minimal. I went with the 7/16" a little over kill..... with only a valve lift of .520"..... Anyway.....
When you change to rollers use die or a black sharpie and color the top of your valve-stems... Then set your rollers.. turn the motor over by hand (make at-least one complete engine rotation).... then pull the rollers and look at the witness mark... It's good to have an adjustable pushrod to check for the correct height... Comp Cams has a good write-up on how to set your roller rockers and they have a nice adjustable pushrod... And it is sickly accurate, (I checked it with an outside mic). When I put my 1.7:1 rollers on I think I actually had to get shorter pushrods???... Maybe Due to milling the heads and block and a thinner head-gasket?.... Hmmm, maybe I had to go .050" longer???? But valve geometry is a must for a long lasting motor (Upper half). Just my 2 cents

[AMX69PHATTY]

When using adjustable pushrods to check rocker geometry does not a pair solid lifters also need to be used to get full travel since the hydraulics will collapse under valve spring pressure and prevent full valve train travel and a true witness mark on the valve stem, and any difference in height between solid and hydraulic lifters has to be compensated for in determining correct pushrod length ?
:-|

[fifesjeep]

When I did mine.. I used the Hydraulic lifters.... and I turned it over a couple of times making sure I had sufficient oil pressure and then marked the valves.... You'll know if you have a change or bleed down because the witness mark(s) will be elongated, so to speak... but in-order to get an accurate or as accurate as you can with hydraulic you gotta check a few valves... But even then The bleed down is going to be minimal... and that's why they have specifics on the setting of the rockers... But, Solid lifters are nice for the complete performance (or next to) of the cam lobe etc. On my next build I'm going with a complete roller set-up. :? Hopefully it'll be a little less wear on the motor over the long range.