So if I were to come across a low mileage L98, 049 cam, and wanted to run it on TBI.. Should I change my pump to allow say 18PSI of fuel pressure, change to 61lb 350 injectors, 350 knock sensor and esc and get a chip tune. Or will it run good with my stock intake, 350 injectors, and a stock 350 chip. I had thought a long time on a Vortec crate but I am getting a nice low-mileage L98 at a deal so I'm going that route. Still going to at the least change valve stem seals, possibly valvesprings, oil pump, seals, etc and may still stick a set of Vortecs over on it. I'm still in planning phase as I have been last 2r3 yrs. Picking up the L98 in a few weeks complete with TPI setup and hooker headers to go with it. Came in a friend of mines 70k mi Iroc that he just swapped over to LS. Not sure if I will stay with stock intake or go with carb intake with TBI adapter. Not looking for lots of HP just nice strong cruiser 250-275 hp would be great. That would be a big upgrade in itself over a 170hp L03. Id like to hear from anybody who has used a stock L98 with their TBI and how that worked out for them. I like the gas mileage and reliability of this system it has been flawless in this car.

 

I recently acquired an 88 IROC with a L03, and my plan is similar to yours. I don't have the experience tuning TBI like I do TPI, but I'd say run the stock intake, stock 350 injectors, stock fuel pressure on an upgraded fuel pump, and run a stock 9C1 caprice tune to start with. That's my plan on my 88 anyway.

I don't have a good sense for how tolerant TBI is of engine changes. I'm sure a 9C1 tune will not be ideal for an L98, but i'd guess it will be a 95% solution for you. IF you want more power down the road, do a full exhaust, change the intake, and get a custom tune.

 

I have headers and y waiting in the shed for it. Running 14psi spring already but I'm not sure my pump is even making that much so I will go with a TPI pump. Already have 3in exhaust. I may have found someone to burn a chip for me. If you change yours out let me know how it goes.

 

 

Good deal looking forward to reading up on what u do.

 

Here is a good read, you have a 1228746. The code atjp prom with a custom timing table from code aujp 90-92 l98 automatic should work well.
The tables wouldn’t line up kpa wise but it could be made to work.
https://www.thirdgen.org/forums/diy-...uide-book.html