Someone asked about the big block stuff so here is the lowdown on 413 heads on the high water pump version.
They are not worth spit for any performance, but are damn near indestructible and great for the intended purpose of an RV, industrial, or tow engine. The 413-3 engine made 445 lb ft @ only 2400 rpm.
Tiny 1.88/1.50 exhaust valves with chrome stems, exhaust is sodium filled. Hardened pressed in exhaust seats from factory. Water pump housing bolts directly to the front of the heads for better cooling. Heads are much taller than normal big block due to this.
They are also closed chamber head, but with a large 90cc chamber. Peanut plugs in the center of combustion chamber. Special exhaust bolt pattern. Runners look more like a small block than big block.
As mentioned before, 413 piston choices are limited and or expensive for what you get. For this reason I am building a basturd child 440 short block with TRW six pack pistons with the 413 RV heads. Will be set up for .040 quench, 9.25 to 1 compression, and a set of RV headers and 3" exhaust. Using a Mike Jones cam ground especially for these RV motors.
I go back and forth on whether or not to keep the water flowing through the intake. Fuel economy v/s cooler intake charge and less prone to detonation. Leaning toward blocking them off.
As to the 440 RV engines, I have yet to see one that had the high mount water pump. With Chrysler though never say never. Lots of them I have been told are 440's but on closer inspection they have always turned out to be 361 or 413 industrial engines.
Dont try to convince anyone of it though as some people get snorting mad sometimes when you try to tell them. Cousin Jim Bob told them it is a 440 so by god it has to be!
