Engine/tranny swap

[SgtPreston]

Sorry to say my really good running 5.7L Tbi and 4L60-E needs more help than is available to make it a performance engine capable of towing a trailer with a car loaded. So I'm in the process of getting a Blueprint 365 Hp engine with Holley Sniper EFI and a beefy 700R4 to handle the 4X4 off-roading.

The engine is a few weeks away so I wonder if anyone else has made a similar swap that might share some do's and don'ts - or just pulled the 5.7 out for another engine (LS?) to give me some pointers on what needs to come out with the engine - I know the PCM is underneath and behind the glove box and will have to come out. I understand we can strip the wiring harness and just pull out the wiring needed for the gauges - anything else I need to be concerned about that should stay with the engine/tranny?

Any helpful hints would be appreciated.

 

[exp500]

So are you using a Vortec or an LS motor? You will need computer and Harness from a donor vehicle Unless that Holley can piggyback yours. You will definatly need the wiring diagrams, So the Factory service Manual is a MUST HAVE too. A high end scanner and programmer may be necessary depemding what ypu wind up with.

 

[1BADI5]

Depending on the year of your truck the PCM is under the hood in front of the brake master cylinder

 

[SgtPreston]

Jeremy, It's a '94 Yukon and I think I've had the PCM out before to replace blower motor, but I get confused sometimes between PCM and TCM.
J - it's a sbc with vortec heads, roller cam and the Holley Sniper EFI - the Sniper comes with it's own computer to program the FI initially and than it becomes self-tuning based on your driving habits. I'm thinking there will be no more computer interfaces with the new engine/tranny but I wasn't sure of what else I needed to pull out with the old drive train. Thanks for the comments guys.

 

[exp500]

Sgt If I remember right the TBI trucks PCM/TCM is under glove box as you said. So you will use the 94 Dist as the signal for the sniper? Or does it piggyback on 94 computer? I'm not familiar with sniper system. There was alot of reflashing and rechipping that vintage and earlier with every cam or head upgrade.
Maybe you could download the Sniper Installation manual and if you hit a rough spot reading it, we could help you through it.

 

[exp500]

The 700R4 will need a VSS for the dash and cruise Box, not sure if your current one will work.I would pull eng & trans leaving wiring intact and modify the minimum.

 

[swathdiver]

If I remember right, the Holley system is stand-alone, doesn't need original computer to operate.

 

[exp500]

Swathdiver-Don't they all say that? Standalone? So where do you draw the line? Holley supplies a distributor?
Not enough coffee yet, I know theres a question I'm forgetting. I'll shut up and watch.

 

[SgtPreston]

Thanks for the responses - the Blueprint engine comes as a "turnkey" project, complete with distributor, plugs, wires, Holley Sniper (w/computer), etc., so all that's needed is a water pump and swapping over the PS pump, alternator, A/C compressor and the serpentine idler system. I need to replace the fuel pump and install in the tank (higher pressure req'd for Sniper) and I've ordered a flex plate but everything else should be straight forward as a 350 swap for a 350 - how naive does that sound? My concern is what the existing PCM controls (gauges, heater/AC, ABS brakes?) and what can be drilled around. I've only had this truck about six months so I'm not as familiar with it as I should be, or would like to be. Thanks for the feedback.