overheating

Haven't heard that one. Your '99 Indian is a CMC Harley clone, does it have an S&S motor? A high performance motor will carry higher temps even without a sidecar.
Other considerations could be: Timing too advanced. Excessive idling or slow air flow due to traffic conditions in a hot climate. Warped head to cylinder mating surfaces due to previous overheating.
An oil cooler will lower running oil temperatures, how many degrees I don't know.
Do you have an oil temp guage installed? If the temperatures are extremely high I would be concerned about the bottom end bearings and cylinder walls also.
There is a vendor that sells an electric cooling fan for the air/oil cooled V-twins. That may be an option for hot climate running.
If you have the S&S motor, a call to the S&S tech line may be the next step.

Lonnie

It doesn't sound to me like it makes sense to add more power and then de-tune it for cooler running. I'm assuming this is the rear jug we're talking about- I don't think the oil temp is blowing the gasket, I think your head is warped. The rear jug of a V-twin gets hella-hot in warm temps. Don't know the S&S engine, but if that head is aluminium, kiss it good-bye. Like Hackn said, if the engine got hot enough to warp the head, you better take a close look at the bearings, too.
Those engines, I'm very sorry to maybe rain on your parade, didn't have the best rep in the first place. That's a big reason the company was trying so hard to come up with their own.
The reasons for running hot may be the carb is too lean or ignition too advanced. Might want to te-torque the head before checking the valves, too.
An oil cooler can't cost that much, can it?
Keep us posted-

I have a 2001 Indain Scout in my stable. With a S&S engine no problems here. S&S is a proven engine. Timing can cause engine overheating. But the most common cause whith a air cooled v-twin is a lean running clyinder. Check intake manfold for vacuum leak. But also sounds like the heads need to be checked as the other guys have said. A oil cooler will help but the cooling fan is better for in town and slow speeds. That is what I'm going to install on my twincam.

Thanks for all the great advice. I have a mechanic tearing down the engine as we speak and will bring all this advice to his attention. I will update you as soon as I know something
What kind of sidecar do you have on your Indian?
Thanks again for all the help
Steve

My wife rides the Indian. I just finish installing a Harley TLE sidecar on my 99 FLHTC. Ken