289 Heads: Rail vs Pushrod Guided Rockers

[rob289c]

I am going to be reassembling the 289 I disassembled over 10 years ago. I threw out the old rockers back then as I didn't intend to use them. Now I don't know remember style they were.

I think 1966 1/2 was around the time the change was made to rail-type rockers. My car is a '67, built on 30 Dec 1966. Inside the head is the following: 289 66 6M16. On the botton is: 66 289 C60E 44 M.

My "How To Rebuild Small Block Fords" book says the pushrod-guided type should have "close tolerance, rectangular holes" where the pushrods come up through the head. Mine look round to me. There is a table on page 28 for those that have this book and if I am reading it right, C60E-M, which based on the castings is what I have, should be pushrod-guided. According to the table, C70E-A is the first hae with rail-type rockers.

I'm confused; can someone tell me what style of rocker to use with these heads? Any guidance will be greatly appreciated.

Rob Green

 

[D.Hearne]

Your heads are 67 model year heads and thus use rail rockers. Another clue is the round pushrod holes thru the heads. The valve stem tips that protrude above the retainers should also be about 1/4" high. Pushrod guided stock valves barely stuck above the retainers by about 1/16" to 1/8".

 

[fasttback]

As stated before - rail rockers. I would also suggest upgrading to some roller tip rockers. I believe comp cams(?) puts out a roller "rail" rocker if you don't want to go with screw in studs and guide plates. Roller rockers provides less friction and wont chew up your valve tips.

 

[rob289c]

Thanks for the replies, guys. The valve tip definately sticks up about 1/4" and the pushrod holes are round. For now (probably forever) I'm just going to go with stock-type rockers. I may consider the roller tip-type if not overly expensive. I'm going to have a hefty bill to pay to the paint shop when it's done so I'll have to cut corners somewhere and I guess rockers will be one of the proverbial corners. It's only a stock 289 (+ .030), a mild Comp Cams Hi Energy cam, and stock 2100 carb. Just looking to build a dependable 289 that starts and runs everytime like it used to. After 10 years apart, it's time to put it all back together and enjoy it again!

Thanks again for the help with the rocker question.

Rob

 

[68stangman]

If you are going to spend any money on the heads, perhaps having the valve seats hardened would be a first choice, then roller rockers. With the 2bbl setup, it does not sound like you are looking for performance gains, just reliability. There are late model 5.0s with well over 150,000 miles still running with stamped rocker arms.

I would personally get caught up in spending for a new intake, new 4bbl carb, late model heads with bigger valves, roller rockers, an aggressive cam, headers and plenty of high octane gas. That can get a little pricey.

 

[LMan]

If you get roller rockers in the future with those heads, you will need guide plates and hardened pushrods.

 

[rob289c]

10 years ago when I started this project I had all my machine work done (block, crank, balance, heads, etc). I had the heads resurfaced, 3-angle valve job with new,stock-size valves and hardened seats in the exhausts. At this point I'm just going for stock so unless I get a last minute itch, it's gonna be stamped rockers. I built a 289 in 1982 with all the speed goodies of the day; this time it's going to be for easy cruising.

Rob

 

[180 Out]

How can roller rockers work with those protruding valve stems, anyway? Not something I'd want to try. Has anyone swapped a rail rocker setup over to a guideplate/roller rocker setup without changing valves?

 

[D.Hearne]

How can roller rockers work with those protruding valve stems, anyway? Not something I'd want to try. Has anyone swapped a rail rocker setup over to a guideplate/roller rocker setup without changing valves?

Yea, it's done all the time. As long as you've got guide plates and hardened pushrods and the right length pushrods, the valve stem tip length has nothing to do with how it works.