I'm making this post as I knew I needed injectors awhile back, but there is some spotty info on the Ford injector swap about fitment. I'm hoping to clarify any issues while I've got everything out. Just bought a set of M-9593-A302 24lb injectors from Summit to replace/upgrade the (old/bad) stock 350 injectors in the motor now.

Summit Part # FMS-M-9593-A302 Price 295.95. (injector kit of 8) Yes they've gone WAY up in the last couple of years. (used to be just over $200)

I grabbed a GM fuel rail from a swap meet that was mixed in with a bunch of other parts for the injector "locks", the style that are half moon shaped with one large tab on the end to push or pull for removal/install of the injector. Anyways, point being, I have no idea what this rail/injectors are from. I suspect a 4.3L, as the rearmost injectors are paired while the front single ones are a good distance away. I don't believe the 2.8's or any other motors would be spaced like this. In any case, I only mention in case it is possible these injectors are NOT like the stock Camaro ones. I don't want to mislead, since all my measurements/comparison are based on these.

Overall Length is:
FMS 3.037"
GM 3.135"

Lower O-ring seat lip to injector tip:
FMS .272"
GM .286"

Locking groove to top of injector:
FMS .358"
GM .450"

O-ring diameter:
FMS .563
GM .561
Disclaimer on this measurement: GM o-rings were used, and the test was pretty subjective...very light pressure with the dial caliper jaws, whatever spring pressure the o-ring exerted back was allowed to expand the jaws.

O-ring thickness:
FMS .137"
GM .150"
Even used, GM o-ring is a fair bit thicker...replacing the Ford o-rings with GM is suggested elsewhere on this board.

Upper o-ring seating surface diameter:
FMS .307"
GM .308"

And since a (bad?) picture is worth a 1000 words:




Look to me like everything is well within spec of the GM injectors, and can not cause ANY problems, although I'll be changing out the o-rings, if anyone cares to mic some new GM o-rings and add that info.

 

The ford injectors fit just fine. I put those same 24's in my 350 tpi with no problems whatsoever.

 

Dido.....I have had the pink top on mine for two years now. 22lbs. No complaints. Your set-up shown will work fine. Double check to make sure you don't "bury" the injector all the way down to the intake opening.

 

I put a set of Blue Tops in my IROC many years ago. I did use the GM orings, but I never had any injector related issues (other than improper tuning)

 

Can the Ford 24lb fuel injectors be used on a stock long block 350 TPI with TPIS Big Mouth manifold, Accel runners, 52mm throttle body and ported plenum?

 

if you used that setup with the stock injectors, you should be fine. stockers are 22# and the ones you want are 24#. you will probably run a bit rich, but probably not. not to big of a difference plus your getting more air in so it should even out somewhat. if you notice you are running to rich, yu might need to invest in a chip to tune your car

 

Are the O-rings you speak of the o-rings that go into the fuel rail or the o-Rings that go into the manifold? Which O-rings do I need to replace with the GM ones? Thank you.

 

Both of the o-rings should be replaced IMO. I read some older posts regarding the o-rings, at one point the Ford ones were the same or much more similar to the GM ones.

When I replaced the injectors I made the mistake of not measuring the GM "blue" o-rings that I used. They were obviously larger in diameter than the Ford ones, moreso than my above measurements show.

I wouldn't take any chances with pressurized fuel, buy the gm o-ring kit if you swap to ford injectors. The part number for the kit is on this board somewhere, I found it by searching.

 

Are the ford injectors supposed to ohm in at about 16.5-17 as well?

I've got some out of a f-150 5ltr but have no way of IDing the flow rating. What should I look for when I pick them up?