Been a member of the site for several years, just keep loosing my user access... over and over.

Before I make my decision I'm looking for expert advice on upgrading the cam both for better performance and to stop the reversion issues. Reversion being the obvious "must stop" issue but I want to stay as durable and reliable as possible.

I have a 99 HP 500 Carb'd - Serial# OL415762

So far what I have had done is the stock heads were mildly ported and the bowls had moderate work also. Intake was matched to the heads and cleaned up the runners. New Isky tool shop springs matching the originals, 2.25 intake valves & increased to 1.9 exhaust valves all with thinner stems and titanium retainers. New 8954 Comp lifters, original rockers and push rods.

Everything else is stock including those good ol' water sucking Gil Manifolds and risers.

The question I have after reading everything on this subject is... should I go ahead and go with either the EFI version cam 731 or 741 or will it make a significant difference to go with another cam entirely. If the stock EFI cams will work best which one would fit the head work best?

Try to find a 525EFI cam. Its a Crane 741 ground on a 114 lob sep instead of the standard 112. The standard 741 will also be fine with a 112 and you should not have any reversion issues.
The stock 500HP carb cam is way more prone to reversion than either of the others since its a 110 lob sep.

im running the crane 741 in both my hp500 with stock gill exhaust with no problems.

From what I hear the 741 works well. Or you could get a cam from RMbuilder.

I used the 741 with stainless marine exhaust with custom made pipes made by SM that dumped the water at the end so not to have any reversion issues. And it sounds awesome.

I used the 741 with stainless marine exhaust with custom made pipes made by SM that dumped the water at the end so not to have any reversion issues. And it sounds awesome.

I used the 741 with stainless marine exhaust with custom made pipes made by SM that dumped the water at the end so not to have any reversion issues. And it sounds awesome.

Simple enough... Questions
With the 741 (112 or 114) cam...
does the timing remain the same as HP500 Carb spec (14/34)
are you guys able to get the idle back down to spec (700-750)
did you guys have to re-jet the carb?


Thanks guys I appreciate the input a bunch...
John

my timing is at 36@3000 and i sent my carbs out to nickerson for a full competition carb rebuils and they idle @800 and work awsome. i also run msd boxes with msd distributors and gap my plugs at 45.

Yep. rmbuilder aka Bob Madara can be reached at 585-654-8583