I have a complete tpi intake manifold and fuel rails that came in a junk car when I worked at a junkyard. How would I tell if its a maf or sd setup all I have is the plenum, base, runners, and fuel rails? Are there casting numbers that I could look at to tell the difference?

 

IIRC all that is interchangable between maf and sd systems. Now if you got the TPI setup off a vette it will likely be different as they use a different egr setup, ect... Post some pics.

 

SD systems should have two bolt holes on the passenger
side of the plenum to hold the MAP sensor in place, no?

 

heres the pics thanks in advance for the help

 

It is a MAF TPI setup, note the cold start injector bung on the runner
and the actual injector coming off the back of the fuel rail itself.
Chevy omitted the cold start in 1989, SD systems were introduced
a year or two later.

So it is a Mass air flow TPI from 1985-1988.

 

Is there any way to convert it to sd to make my wiring easier in my application

 

There isnt a real big difference, you can keep the injector there so it doesnt
create a vacuum leak, just dont plug it in or use a prom with cold start operation.
Which shouldnt be a problem if running speed density.

Im fairly sure you can use it with SD, I think you just have to
find a place to hang the MAP sensor, someone correct if I am wrong.

 

I was looking for injectors on ebay and found a billet blockoff plate for the 9th injector and what tpi is saying is that I can just buy a map not a maf and I guess follow the vacuum diagram from the sd tpi and everything should work out. So are the rest of the sensors the same from the 305 and 350 and sd from map?

 

Pretty much, there is no big conversion honestly.

Your going to have a extra hole on your intake manifold from the
cold start injector switch as well. It is a big ugly sensor.. sits right
next to the hose nipple in front of the intake, you can keep it there
as a plug, or remove it, whatever you want to do.

SD uses all of the same sensors as the early systems, other
than the MAF/MAP difference and the ECM's that run them. Im not
sure about MAP sensors in detail, whether those sensors differ with
displacement or not, I cannot say in my experience.

The 305/350 knock sensor is different, you'll need one of those.