Originally Posted by Jeepomat
I am new in this Forum and i write from Austria, but my english is not so good,sorry.
Also i am searching for a Roller Rocker Arm Kit for my XJ 242cui 1989.
What does it bring on HP
Where can i by something?
I can't comment on what HP this mod offers. Claims from manfactures are 10-25 HP. I do have a set on the Ford 351W, but I can't make any comparision. For the Jeep 4.0L, the selection is limited and relatively expensive. MoPar has a set. They are $120 each and you will need 6 sets (one per cylinder), plus a spacer for the valve cover ($75). Hessco sells a complete set.
At this point it might be your best bolt on option. Still, pricey at $650.That includes the valve cover spacer. Clifford is looking for a distributor. I don't know what price they will be, when available. Crower sells a set ($316). From description some modification to the head is needed (machining). I would guess you would need the valve cover spacer. Theese are rail type rockers. No need for guide plates.
Some say Harland Sharp makes a set for the 4.0, but I don't see it listed on their website. Others reference a website that uses Chevy roller rockers. It takes some machining to adapted the Chevy roller rockers. From what most people say, this modification doesn't produce the power (some say none) for the money involved (and work).
I have looked at other options (Ford Pedistal type), but nothing I can say will work. I think at this point the best option is the Hessco. Most say its the last power mod to be made.