Indy/RHS Heads

OK Guys,
Here we go, this is what I've come up with. Because of the lack of the right length valves in 5/16 or 8mm the heads will have to use .200 long 11/32 valves and .050 raised locks. The reason is the installed will now be 1.780 and with the guides cut down you will now have enough clearence for high lifts of the camshafts. With a seal installed you'll have .650 from the top of the seal and the bottom of the retainer.

The springs that are needed are the comp. cams springs #'s 974, and 942. The valves that are needed are #'s F 6147 and F 6206, 6147's are 1.60 and the 6206's are 2.02's but I'll cut them down for flow. This way std. chrome moly retainers will work and are available in both 7 and 10 * versions, this way I can use the 10* version and get the .050 locks cut for lash caps. This is the cheapest way that I can see and get the strength in parts for high RPM's. Here is what they flowed after the valve mods were done.

lift...........int.........exh.
.100.........81..........77
.200........138.........116
.300........208.........151
.400........249.........196
.500........293.........204
.600........302.........209
.700........307.........201

This is what they flowed out of the box with stock valves and no work in the ports or on the seats.

lift...........int...........exh
.100.........91...........81
.200........143..........126
.300........208..........157
.400........236..........198
.500........249..........204
.600........249..........204
.700........249..........204

The exh. side wasn't touched on either flows except in the bowls on the modified port. You have to keep in mind that the modified one was flowed with a 11/32 valve and the stock one was flowed with a 5/16 valve. The exh.port is so good as cast that no real work is needed. I didn't gasket match it or reshape the guide, doing this will increase the flow greatly but IMO I didn't think that it was needed.

All in all if the cam wasn't so large the stock magnum valves could be used, and there are springs available for the retainers. The only thing that I could see that would need to be done is the guides will have to be cut down for lift clearence and seals. If this is the case then back cutting the OEM valves will give you these flow's.

lift.........int...........exh
.100.......85............87
.200......137..........132
.300......207..........192
.400......241..........201
.500......293..........202
.600......293..........204
.700......289..........204

The installed height would be 1.64 with factory retainers and locks. I'll post some pictures of the work later today.