Dont know if this belongs in the TPI or TBI section but I just picked up a91 firebird convertible LO3. My plan is to fix the stupid little things first - like the 20 year old suspension that must be beat to crap. Already ordered bilsteins.... but any way my plan is to drive it this summer take it off the road in the fall and swap a L98 in it over winter.

What kind of cost do you think will be associated with making the swap? I figure i can pick one up that comes with the ecm and engine harness.

What are the biggest head aches in making the swap? - i assume getting the gauges to work with the new setup got to be a pain in the butt. but i do know its been done a million times. So was just looking for some feedback from you guys that have done it so i know what to expect.

In the meantime what kind of stuff can i upgraded over the summer that will swap over? I assume i can do the exhaust from after the cat all the way back with flowmaster 3" system and that will swap over correct? ALso plan on doing teh suspension over and add subframe connectors.

Id love all and any input

Thanks

 

my suggestion is buy a rotted/crashed L98 car and just swap everything you need over. that way you aren't getting nickel and dimed for all the little sensors and junk. Plus you'll have the better disc brake rear end and you can swap complete dashes instead of repining your tbi.

 

would things still need to be repinned if i got a ecm and a harness from the car the tpi is soming from?

 

if the donor car is the same year as the tbi car you shouldn't need to repin anything, assuming you get a complete harness.

I think the biggest headache will be swapping the fuel pump
also you will want to upgrade the exhaust. the stock 2-1/4" tbi system will be a big restriction, you might also want to think about subframe connectors.

 

yeah i am definetly doing subframe connectors first because its a convertible. since i dont plan on doing the motor until next winter i was going to do the suspension and exhaust this year before the motor. Would i be correct to assume that if i put a flowmaster system in there with a 3" pipe from after the cat back that it will swap over to the new motor? im pretty sure its the same exhaust but i could be wrong...

so i guess i can save myself alot of headache if i get the 5.7 tpi, ecm and harness from a 91 since mine is a 91?

i figure about $2000 - $2500 in parts and alot of headaches to complete the swap

 

change the "y" pipe and cat as well, and make sure you get the exhaust manifolds for an L98, and, just my opinion from personal experience (I did this same swap 20 years ago)
3" is overkill for a stock L98. 2-1/2" will do the job without any noticeable losses

 

probably going to make some upgraded on the l98 before install so thats why i was think 3" and shortie headers