I tried posting to this this morning and the BBS went away. A few minutes ago the question went away. I think we still have some bugs.
=================================================================================================
Roller Rockers? Yes, it took me awhile to find out this much.
Mopar does sell roller rockers for 4.0L head. I think that they are a little expensive. $80.91 per cylinder is the discounted Jobber Price. That's $485 for the set. I am hoping that this price list is wrong. Last year's the price for a set of 6 was $242. I was thinking that was too much. I think the $ per Horsepower ratio is very high for this upgrade. What will this give your motor maybe 10 or 15 more HP?
I beleive that we have an alternative, but I don't know anyone who has tried it. The 258 and 304 share the same valve train parts. Push Rods, Valve Springs, Retainers and Rocker Arms. I used my stock 258 Rocker Arms on my 4.0L Head when I replaced the head. The only difference that I could find between the two rocker arms was the size of the hole at the bottom of the rocker arm. One was rounded and the other was squared with rounded corners.
I think that you could use a rocker arm that was designed for the 304 on both the 258 Head and the 4.0L Head. Last time I check the price they were less that $200 for a set of 16 roller tipped and would not required a valve cover spacer. I haven't check the price recently. You might want to call one of the cam makers and see what they have to say.
I also have a message into Mike at ProTech to see what the current price is for the Mopar Performance Rockers.
Let us know what you do and how well it works.
Tim Weaver
89-YJ 258MPI, 4.0L Head, Auto