Posted by George on Sunday, September 29, 2002 at 5:49PM :
In Reply to: "performance" 230, chapter 2:planing heads posted by Ryan McNabb on Sunday, September 29, 2002 at 7:58AM :
Yes, a machine shop that does engine work can easily mill your cylinder head. I think this is the single cheapest thing you can do.
now how much is the question. If it was not milled before, and most have not been, then 60 thou off a 230 head should be ok. As noted in another post, 80 thou off a 251 has worked. 60 thou gives less than a full number increase (ie less than 7 to 8)...but you really would need to measure the combution chamber volume before and after. If you knew the head volume, you could estimate the volume removed by removing 60 thou of f times the number of square inches (which you'd also have to estimate due to the irregular shape). I have not done either yet.
if you have a performance cam installed, be sure you don't have any increase in the valve lift....that might interfere with a milled head.
As for carb question, I suggest using a 2 barrel off a 57 and 58 (I think) Dodge 6. The Plymouths did not have this ever. Get the manifold and carb if possible, but you can probably get a 2 barrel carb to fit from one of the carb vendors. You'll have to search junk yards but I found one this way.
On the split exhaust. I have seen this done two ways. The best is to do what was described before, get a doner manifold and cut it in half. There are guys who do this but I don't have their contact info....their cost is about $150. A second less pretty but easier mod is to cut a hole in the front par t of the exhaust manifold and weld in another flange.
Phillips Performance has sold very nice cast headers...I have a set....but I have heard that he may be out of business or at least is not delivering these in a timely way. You will have to check on that.