computer swapping

[6 and 1/2 liters]

hi i was wondering if anyone has any experience in turning a s code truck into a f code by switching computers? I have one lined up out of a 3500 hd to into my 1500 but mine is 4x4 and the hd is not? Will this work? I heard there is quit a bit more power with the f code computers. Also what is the difference between L65 and L56 as apposed to F and S

[Patrick m.]

basicly an egr valve is the difference, of course one intake will allow an egr and one wont.
i think the computers are the same, it is the chip that is different.

So get a performance chip from a vendor here, get the intake off the 3500 truck you speak of.

[6 and 1/2 liters]

There are no chips from 96 on only complete ecm swaps

[john8662]

6 and 1/2,

Please update your signature with your truck information, that helps us better know what you're working on without stating year, tonnage, etc. every time.

This is done under the User CP in the bar above, then signature.

You're right for a '96 there is only complete ECM swaps, no e-prom.

I can be done, but I think you may run into problem with security programming, not sure, others will know better, I'm in the dark ages with my 95 OBD-1 stuff...

[Dihrdbowti]

You know Matt Max did that very same thing and I believe he then ended up getting his ECM reprogrammed through Westers and is very happy the last I heard. There were a few other issues he had but i can't seem to locate that thread.

[jjgmc96]

there is a lock in the newer computers, i think 98 and newer. it can be over ridden maybe with a tech 2. i bought a unit from a 99 1 ton van and it would not work in my 96, until jk fixed it for me. i also carved out the air intake and lost the egr valve like what was posted on kennedy's site.

[6 and 1/2 liters]

Did you see much in the way of gains? Was it worth the effort of switching to the other computer? thanks

[jjgmc96]

i have had this combination for awhile and can't say if there was much of a gain. on paper the 99 programing allowed for the most hp and torque. i drive with my foot in it all the time and still average 17mpg empty and 12 towing. 3.42 gears, 265r15 coopers, 1600rpm at 59mph and 1850rpm at 69mph, 10 - 12 psi max boost, next thing i need to do is timming chain, gear drive, water pump and harmonic balancer. have 140,000mi. on them now. i have been taking the boost controller off in the winter, maybe this year i'll put the stock computer back in, 2wd is all over the road on snow and ice.