87 chevy tbi

[berezy]

have an 87 chevy 4X4 with 305 tbi.  Want to put in a pre-86 350.  I know the manifold bolt holes need to be modified but will this combo work??  Anyone done this before??

[roundedline]

If you are going from 305 to 350, you might need to bump the fuel pressure up.  From the factory 350's had bigger TBI injectors and a different chip.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[DnStClr]

Most guys want to stay with tbi in their 87s. You can get a 350 engine for it or build up the 305. Some of the 305 parts interchange with 350 parts. There's enough  knowledge on this site to help you through it.  

 

[drewmech]

stay with the TBI way better then carb plus with a little bit of know how all that smog @#%$ just becomes decoration for the state inspectors. if you go to www.moates.net it'll sell you all the stuff to modify your ecu (everything is barely 100 bucks) and hook it up to a lap top for tunning. it's a lot like tuning those rice rocket cars with out actually having to drive one. if you look around you can find a crate 350 for that tbi for around 2 grand. after that you can do what you want to the motor cause you control the ecu with data logging and auto learn modes you can go as big as you want. www.binderbulletin.org look under the forums on the top left of the page then injection talk start with the sticky. any post by bill usn-1 will help you. he's one of the smartest guys i know. plus i love givin him guff about running chevy parts on his beloved international scout.  

[82Silvrdo454]

I've put a TBI 350 in place of a 305 on an '87.  It was the cheap way, and the guy didn't really care how it ran, because he didn't want to fork out any more cash than he had to.  I used a 350 long block and basically bolted it in place of the 305.  It ran OK, but I admit, it could have run a lot better.

[VileZambonie]

I have also heard people say the injectors on the 305 are smaller and run lower fuel pressure however I've yet to see this. Both engines use the same in jectors by part# and the same pressure. The ECM is calibrated with a mem-cal for different base injector pulse width that's all. Fuel trim is monitored by the O2 so nothing should be different except the prom (chip) in the computer.

Fuel Injector 17112493 $220.94 (350)

Fuel Injector 17112493 $220.94 (305)

[Blazin]

Sounds to me like you want to put a pre 87 non injected 350 motor under your 87 305 intake, right?
If you go the route of modifing the manifold you should have a machine shop recut the holes for you, I think it would be worth the $. You could use the 305 heads as well. I think the valves are smaller as are the combustion chamber ???, But if you are only useing it for tranportation etc. I think it would be O.K. You could have a quick valve job done too.
As far as the computer you could go to the bone yard and get one for a 350. Like Vile said they both run the same injectors.

[drewmech]

a rebuilt oem spec 350 tbi motor shouldn't be more then 2 grand if  you look around you could come across one less then that the ecm's are the same slight difference in the fuel tables go to the junk yard and find ya a new chip. that's teh cheapest easiest way i know of