2.25 rocker arm

[MerlynIIa]

Will the rocker arm assembly from a 7.1 head (from a 1965 IIa) work on a 1974 8.1 head? I have a complete IIa engine and a Series III engine without the rocker arm and valve cover. I would like to rebuild the series III 8.1 head with the hardened valves and then use the rocker arm and valve cover from the IIa head. I had noticed some rocker arm parts on the IIa assembly are IIa specific in the Rovers North catalog, so worried they had some differences. Thanks!

[I Leak Oil]

I think in most cases the entire thing will just bolt on. The only possible issue I could see is if you had a really late III head then you might run in to an issue with the metric-SAE fasteners. I'm not 100% positive about that though. As long as you use the entire IIa assembly I think you'll be fine. Easy enough to find out by removing the 6 or so bolts and letting it rip!

[allende]

Check pushrod lengths, they are different lengths for 7:1 and 8:1 heads as the 8:1 head is about 0.10 in less in thickness. The later heads are metric. One issue I encountered was not having a metric threaded banjo bolt for the oil return pipe. Had to craft one using a metric bolt and drill press. Also look at the rocker shaft and see if it's worn. If so you may need a new one. If you get a new one, the rocker arms will have to be honed to fit. Take a look at: http://www.lrfaq.org/Series/Engine.CylinderHead.html

[MerlynIIa]

Appreciate the information, will check things out further before we get to work on it. again, thanks