I have always had good success with the guys @ Arnolds Motor Supply there on Waterloo road.
There is a good machine shop up near Mason City, too....Grawmondbecks (sp?). They are on Hwy 65/Federal Blvd just south of town. They do lots of SB & 5.0 and later model Ford build ups.I can PM their phone number if you wish.
Thanks, I just talked with a guy that's in Evansdale (next to waterloo). He seems very knowlegable with the 351C's. I am going to go see him Wednesday.
I have been noticing blue smoke at idle, and he suspects the valve seals are riding up the valve stems. Sounds like a good reason to me.
Let me know who you talk to about the C4. I have a C4 in my car that needs some attention, and not really sure who to take it to. I was thinking about L&M Transmissions in Cedar Falls, but if you find someone else who knows quite a bit, I'd be interested.