[Bummo]

Not a new plan really but a little more complete. I am taking my 400, 727 tranny, and tcase, rad, a few odds and ends, and putting them in my better bodyied RC. Well, I want to build up a propane specific BB but I cant do it all at once. So I am going to pull the 452 heads off the 400 when I do the swap, and put on a set of closed chamber 516's and a 4 barrel intake. The 452's will go onto the 383 I have arranged to get this week, which will get 30 over forged speed pro's that with the big chambers should generate about 11:1. The 383, with forged crank and 516's is $150 cdn. Already picked up a 361 long block with 516 heads, forged crank, and a few little extras this week from one of our BC chapter members, so now I have 2 forged cranks and 2 sets of 516's. Anyway the 11;1 and large valves and induction hardend seat should work well in the 383, and it should have lots of power. The cam will be reground locally, got a msd 6 and a "ping" control set-up for the dash, and a torker single plane for the propane. A high volume oil pump, deeper pan, a double roller, and MAYBE some variable lifters will just about complete the package. So I think it is a good selection of parts and I get to do all the misc other stuff like a little body work, tranny shift kit, etc while I am still driving with the 400. Anyone pick some flaws in the logic?

 

[txs]

Do you do a lot of driving with this rig, 516s do not have hardened exhaust valve seats, for occasional driving ok but don't think they'd hold up to daily long commutes very long. You might use stainless valves and rotators on the exhausts. Also I wouldn't try porting 516s, the water jacket is in the humps in the top of the exhaust ports, do very little grinding on the roofs.

 

[Bummo]

The 516's are just to run on the 400 untill the 383 would be complete. That will probably be well after the summer though. If I see some cheap stainless exhaust valves on ebay I might stick em in but I am going to be using the 452 on the 383, so not much cash will likely go into the 400 if it can be avoided. I wouldn't bother porting (with the templates) the BB heads for my purposes. Undercut the valves and gasket match is fine.