dodgycanuck,
not a problem. I am glad I made some sense.
You can run 1.8 BBC rocker arms if you choose, don't need to stick w/standard BBC ratios. Might require opening up the pushrod guide holes & run pushrod guide plates?
I personally have not tested nor have heard/read any testing of a blown/turbocharged 250 engine running lumps & testing w/out lumps on a dyno or testing track testing.
But, IMO, I do not think there will be a day & night difference between the two scenarios, a boosted engine w/& w/out lumps.
If you want to get every bit of HP & torque out of your 250 engine, I think there will be a slight advantage of using the lumps on a blown/turboed engine, they improve port velosity & improve the short turn radius.
Where it (the 250 engine) will see more of a benefit I.M.O., is from increasing the port velosity ,(decreasing intake port volume) as compared to the better short turn radius, not as important when forced induction comes into play.
A stock head will do, but if you want every bit of power out of your engine, just remember this ,,,, most all of the power comes from a decent flowing cylinder head.
If you use stock size valves, that will be a hindrance.
If you do not cut down/profile the intake boss that will be a hindrance, if you use a muffler w/chambers that = hindrance, If your exhaust system uses 2" pipe that = hindrance. Get the point?
If you can improve any or all of these things I mentioned, it will all add up to a more powerful engine.
It just boils down to how much effort you want to put into your engine/exhaust system combo.
When you get a camshaft for your blown 250, get a custom grind camshaft from CompCams & go with what they recommend.
I would recommend a camshaft w/a lobe center of 115 or wider.
MBHD
