i've been told by a few people that i can build my 300 up to have about 500 horses but every where i look on the net is just a bunch of stock rebuild junk, i'm lookin for performance parts, where should i go and what all can i do??  

Who told you 500HP?? Maybe with a supercharger and some serious RPM's too but otherwise figure on about 1/2 that with a power band that still is usable in a 4x4. Why are you looking for more power? (what reason or problem are you having)  

it has 8 inches of lift in it right now with 36 inch super swampers. the motor is great only 35k on it stock and it's an 89. i was thinkin about goin with a bigger tire size so i was seein if there was anything i could add on for the extra horses. i have new intake and flowmasters on it so far. don't want to drop a new motor in like 351 because of the price and plus i love the L6.  

What you really need to do based on your setup is a new set of axle gears. It will make a world of difference and make it feel like you had a engine transplant! Your 300 is a good mill but you have asked it to do too much with current axle ratios and tires which made effective ratio taller and makes engine work harder before you even figure in added drag from lift. No exhaust, intake or what have you is going to fix this but gears will as they are the great equalizer here. Try some 4.88 gears in it and you will be quite pleased with the results. Antone that tells you that you can fix it with some engine mods (like intakes and exhaust and such) is blowing smoke at you and wasting your time and money.  

people are always talkin about 4.56 gears. don't know much about gears, just learnin about it as i go. so you say 4.88 is the way to go. what would be the difference in those from 4.56?  

4.88 will give you a little more power than 4.56 (better mechanical advantage) and also if you think you might go a little bigger in tire it gives you more to work with too. Your truck should have a OD tranny and 4.88 will improve OD performance a lot too. If you had a 351 I might agree on a 4.56 but with your engine I would say 4.88.  

cool, sounds good, thanks for the help.  

One more thing when you think of deeper gears, think of them using as a bigger longer pry bar/lever to move a load. You have to work harder with shorter lever to do same work and you can do same "effort" with a bigger lever with less input and apply even more effort to load with same effort as with a smaller lever. The deeper the gear ratio, the bigger the "lever" that engine works with.  

I agree with Snoman on that 500 horses seems a little far fetched. You always want to start with regearing first to make up for loss of power, unless engine is just flat out tired and wore out. In your case with a healthy 300 with that low a milage your golden, I wouldn't touch a thing except bolt on power additions like exhaust and K&N aif filters. Those type of additions are good for a little extra power and help a little with fuel economy(emphasis on little economy). I also would have to agree with the 4.88s' that should really make up for the bigger tires and lift, that and the additions I mentioned should put your truck alittle above stock performance.