5.7 Vortec to 5.0 Vortec

[Manimal]

Ok I have searched and everything has come up the opposite of what I am asking. I have a 99 Tahoe 4wd that had a bad engine(5.7) I have a 98 C1500 ECSB with a GREAT running Vortec 5.0. What issues,if any, would arise if I drop that 5.0 into my Tahoe and hook everything up as was on the 5.7? its the same exact fuel system, emissions system, ignition system. Being OBD II it would relearn itself based on the engines needs correct?

 

[df2x4]

I have a cousin who kind of did this exact swap by accident, but with TBI era trucks/engines. The only issue he has now is that the 305 runs very rich. Personally if you're going to do it I'd get the PCM in the Tahoe retuned for the 305. It may be the same exact fuel system, but the 305 isn't as thirsty. The PCM can make small fuel adjustments based on running conditions, but it's always going to run rich if it's feeding a 305 with a tune for a 350.

 

[Manimal]

I have researched all ignition, fuel and emissions parts and EVERYTHING is the same between both engines. So all I should have to do is have the ECM tuned for the fuel curve of the 305? They use the same fuel pumps, injectors, ignition components, MAF sensors...everything is identical.

 

[L31MaxExpress]

I have researched all ignition, fuel and emissions parts and EVERYTHING is the same between both engines. So all I should have to do is have the ECM tuned for the fuel curve of the 305? They use the same fuel pumps, injectors, ignition components, MAF sensors...everything is identical.

Believe it or not it will actually run pretty well on the 350 tune. Atleast my 99 Tahoe did. I actually had to do a fair amount of tweaking to make it run right but I also had a 218/218 @ .050, 110 lsa cam, headers, and a cold air intake. But it started up, ran and idled and drove well for the most part.

One thing you will run into is GM never made a 305 tune for the setup this becomes. ALL the 305 applications used a more restrictive single cat and Y-pipe.

The 305 running on the stock 350 tuning actually ran lean for me.

 

[df2x4]

I have researched all ignition, fuel and emissions parts and EVERYTHING is the same between both engines. So all I should have to do is have the ECM tuned for the fuel curve of the 305? They use the same fuel pumps, injectors, ignition components, MAF sensors...everything is identical.

Sounds like a plan to me!

I always thought the parts interchange between the engines in these trucks was pretty cool. Even the 4.3L V6 shares a surprising number of parts with the small block V8s.

 

[Chuck_13]

I have a cousin who kind of did this exact swap by accident, but with TBI era trucks/engines. .

That's actually kinda funny,the kind of thing I'd do.......