99 Ford E350 Intercooler

[slk133]

Hi,
I have a 1999, Ford E350 Superduty 7.3 cube van (retired ambulance) that I use for pulling a camper. I have had it for three years now, the van weights 9400 pounds and the camper 10,000 pounds loaded. The van works great but I have found it under powered so I have put on some performance parts (exhaust, chip, propane, water/methanal, gauges,fuel regulator kit(this made a huge differance))
I was just curious if anybody would be able to tell me what else I could do to improve the performance? Example: intake, after market turbo, or injectors. I would also like to know if there are any companies that would make an intercooler kit for this? (I have seen on tv where they mounted the intercooler on the bottom by the front bumper)
Any help you could send my way would be greatly appriciated. Thanks for your time.