[Prowbar]

Not a problem at all. I used cast iron guides for the exhaust, with the positive valve stem seals. Bronze would have been better, couldn't find any in the size I wanted. The engine is assembled, last thing is the cam, because I had some issues with it.

I've read a lot about cam design in general. Tried to stay very mild on the cam, to increase torque and drivability, and get as much out of the engine as possible. No need to try high hp/high rpm tricks if the engine doesn't turn past 3200 rpm.

Those Comp springs are pretty stiff I think but could work. I would prefer 85 pounds of seat pressure. Pete Chronis talked about Ford FE390 springs. For a low RPM engine, this should be sufficient in my opinion. A 5.9 Cummins uses about the seat pressure.

I'd like to increase lift but it has to be doable.

One way to increase lift is to reduce base circle size, there is indeed a possibility of running into geometry trouble.

I am going to discuss with the cam grinder if they can weld up the lobe to increase the lift and accommodate the new profile.

Different rocker arms are also possible. But would need to be custom-made.

Hope it makes sense.