What is the highest HP jetting you can run on the stock bottom end in a 90 L98 without effecting the longevity of the engine? This is with a wet nitrous kit. The motor is going to have Vortec heads, HSR, SLP cam, LS1 injectors, etc. Thanks.

 

0 HP un-tuned, 250HP tuned.

 

There is nobody around here that does tuning so thats not an option. Maybe a mail-order chip..thats about it. He would have to go out of state.

 

If you put a generic chip in that car you won't be able to spary it because it will bump up the timing. You should be able to pull 2 to 4 degrees out with your distributor and get away with a 175 shot without any extra chip tuning. Make sure your ignition and fuel system are in good shape, I put in a Walbro 255lph pump and an MSD 6 box before I sprayed mine, I use stock heat range plus and 2 degrees down from stock timing on my 175 shot.

 

The limitation would be that of the cast crank. I will look around for the Hp max. I believe that the RPM max is 6,000 RPM for durability.

 

You need to buy the fuel parts and timing parts. Fuel is more of a mechanical thing. You have a choice for timing. Either spend your money on a one car / one time use MSD timing box OR buy prom burning equipment that will last you forever. With the prom burning equip. you can tune it even better for more HP than a timing box. The price is about the same. Prom stuff is probably cheaper.
Mail-order is just about worthless. Your max. HP will depend on how bad you rattle it, how bad the parts were previously stressed, how bad they are worn, etc.

 

150hp max

 

Most nitrous kits rate a 350 at 150hp max, they do this because it's conservative and keeps people from saying "that nitrous blew my motor up". A 2 bolt main 350 will handle 500 hp as long as you keep it under 5500rpm so what your motor's making add that to your nitrous shot, and keep it under 500hp and 5500rpm. The first thing to go will be your rod bearings, then the crank. Also factory nitrous kits are rated to run rich in order to keep you from burning a piston, you can usually go a jet leaner on the fuel side, but you need to know what you're looking for, if the car black smokes under nitro it's running really rich, if you cook your plugs (white glazing or burnt off electrodes), you're too lean.