Hello everyone I was initially thinking of reusing my current tbi system. I am in the process of building a 350 0.030 over with flat top speed pro pistons. If you follow my link below as I am using a Lunati lt1 cam that is slightly hotter. I came across a tpi system in the junkyard and I was thinking of converting over. I have always heard that tbi is a pain to tune due to the speed density.

I did have luck when I freshened up my current tbi 305 with a speed pro cs-1079R cam that I swapped in 18 years ago and have been driving it daily in the summer ever since. I never did any prom tuning on this previous cam swap and it runs well on especially cool dry days. This time around going to tpi would probably give me more better performance especially on humid hot days where I found the tbi system to feel less powerful as the open air cleaner element must be sucking in hot air. Lastly I have a set of 193 heads that I previously got from the junkyard as I was going to use when I built my 350. I would greatly appreciate some help

https://www.lunatipower.com/efi-hydraulic-roller-cam-chevrolet-lt1-lt4-279-287.html

 

I stayed with the TBI and just upgraded the system, bigger injectors, 46mm bored intake and TBI, more fuel pressure, L98 cam, better pistons and lil porting on the 083 heads and it runs really good! I still like the looks of that TPI setup if thats what route you wana go but adding 75-100hp to your TBI engine is easy and simple.

 

Thank you, you have have motivated me!!

Some part of me always felt that TPI wasn’t worth the headache for a small amount of power

 

These MAP ECMs do have some ability to adapt to modifications. What happens is that the ECM has a range of adjustability on the non-WOT fuel trims.

If your mods don't cause the ECM to max out at either end of that range (lean or rich), you may not notice anything detrimental without tuning... and it may seem like the car runs just fine (since it is). Though in reality you may still be leaving some non-WOT performance and driveability on the table, since the closer you are to the center of that range, the better it'll run.

On the WOT fueling, GM already goes a bit rich on factory calibration, so with the cam you're proposing, I don't see much risk of going too lean.

At 213°@.050 on the intake with a 112° LSA, that should give you a nice well-mannered street engine that you can have a lot of fun with (and probably still pass smog if you need to). Plus it'll be well within the performance range of the TPI intake and your proposed heads.