This seems to be a redundant topic on Thirdgen.Org, but I'm doing a 305 --> 350 swap. I have an '86 IROC with Tuned Port Injection (TPI). I was interested in purchasing the 300 hp TPI engine from GoAutoCenter.Com, but the description says the engine is recommended for 87-89 TPIs. What kind of problems will exist if I choose to install this engine??? What parts will I need and what modifications will I have to do???

I bought the same motor last year, but with the TBI cam (my RS still has TBI.
Mine's a 92 and I didn't have any trouble installing it.
You may need the 350 injectors, but at least an adjustable fuel pressure regulator.A custom chip will also help you get the most out of it.Mine is from Ed Wright at Fastchip.com.
Any 305-350 swap should include the 350 Knock Sensor and ESC Module, AC/Delco Part#'s 10456288 and 16128261 respectively.
So far I've got 13,000 miles on this motor and have had no problems. No monster, but makes way more power than the 305 and pulls hard to over 5000 RPM.
-Rich-

Thank you for your input RICH92RS350!

The reason I started this thread is because I believe 1986 TPI manifolds and 1987 TPI manifolds are slightly different. Isn't 1987 the turning point for a different head design? Will I need a different intake manifold? Can I modify mine?

It's just the middle two intake manifold bolts that are a little more vertical. On carb and TBI intakes, all you need to do is enlarge those two holes a little bit and it works fine. On a TPI, I suppose you could do the same, if there's room. If not, then yeah, you'd have to replace the intake base.
-Rich-

just wondering on a update. I am also trying to research into something like this option, however i have a 85 firebird and it's manual...

Anyone got some basic insight where and what i should look for? I'm not lookin for a dragster (that'd be nice though)
but i would like some good serious street power.
Thanks for your time and help