what should i buy? ls motor

[sman]

As far as your o2s go, if the car wasn't tuned to delete the rear o2s then the car would freak out as the cats that are missing aren't cleaning the exhaust and would freak the computer out. So who ever removed the cats probably had it tuned to delete those o2s and just kept them in to plug the bungs so there wasn't an exhaust leak. I run a FAST dual wideband o2. Once for each of my headers, so I can look as both banks of the engine.

Bolt on subframe connectors can we welded on if you want and bolted, if you want to remove weld on ones it just takes some grinding.

As for the nitrous I am not familiar with how much juice a ls internals can handle but if I recall they can hold like 500hp on the rods. With a 250 shot I'm pretty sure you will grenade the 7.5" 10 bolt. Also a T56 from a Fbody is only rated to like 450ft lbs at the the flywheel.

A car will run on higher octane fuel then it is tuned for. Octane is just the resistance to detonation. If your car is tuned to run on 91-93 octane its pointless and a waste of money to run anything higher. The PCM already has the max timing set for 91-93 and its not going to go, oh check it out 110 octane fuel I'll just bump up timing by 5 degrees. Doesn't work like that. Now running lower octane will mean you will see knock/detonation because obviously lower octane means you have to cut timing back.

Also, most higher octane fuels contain lead. Which is a death sentence for o2 sensors....

[Fox Slaughter]

If your car is going to be a strip demon I say go ahead and tune her for race fuel. If shes gonna be a street prowler/strip warrior then I say go for pump gas. Just because obviously its cheaper and you can fill up anywhere. If you are really worried about the loss of octane then just run a water/meth injection.

[TRY MEH]

i dont launch my car much at all and will never launch it off nitro. i run 91 sometimes 93 but i have mixed it with race fuel.. mainly to see for a differnce my motor had spark knock here and there "once in a great while" car runs rich on pump gas i can smell the fuel its not overpowering smell but i know its rich...

the car runs great though.

[Fox Slaughter]

Remember its going to smell different also because the cats are removed.

[TRY MEH]

its rich..

[Fox Slaughter]

At idle? Most cars run slightly rich due to the inconsistencies in fuel and its better to run slightly rich then lean. This is where a wideband and a tune comes in handy.

[hoogiesngrinderz]

I have a feeling the car has been tuned, or has o2 simulators.

The front o2's should be taking care of the fuel trims - unless it has an open loop tune...which it shouldn't, not with a stock cam. Put in a WB o2 to confirm.

[meissen]

If the rear o2s are literally hanging there while plugged in ... Just not a good idea. Those suckers get hot.