View Full Version : 95 GMT400 LM7 Swap - 5.3 in my Silverado

06-09-16, 07:33 PM
Time for another build.... :lol:

This is my '95 K2500 budget truck project. It's also my daily driver. I picked it up around a month ago, in pretty tidy condition considering its age. It was the cheapest one I could find and it does have a few issues that I'll be working my way through fixing. But it runs and drives OK.

It's a TBI 350, slow as hell. I bought it to use as my daily and also to tow my Camaro to the track when I start to get a bit more serious with it.

First thing I did was give it a good service and changed most of the fluids, the only thing left is the front and rear axles, I just need to get some oil for those.



Given that it was so slow I gave the throttle body a service, turns out it didn't fix the problem, but hey it's clean, and I did some quick modifications to it as well.



The motor smokes a little bit when you lift off the throttle, did a compression check and all cylinders were at 170-175psi warm. So I'm sure the bottom end is good. I expect it's just the valve stem seals. So with that in mind I priced up doing a top end rebuild and then some upgrades on the motor. Right at that point a 5.3 LM7 and 4L60E came up for sale, so I bought that....as you do...

Plans are to stick a mild cam and valve springs in it, rebuild the 4L60E and then drop it in. I'm now in the process of gathering parts and information to do the swap. Looks pretty simple right now....

Pulled the heads off the motor, a bit of water damage in 2 of the bores. I think it will hone out so just a new set of rings needed. While it's apart I'll replace the main and rod bearings too, seems silly not to really.

Other than that it looks to be a good clean example of a 2002 5.3....

The AC pump is siezed solid, and I don't have a mount for the alternator, although I do have the alternator itself. The PCM is the wrong one, has 4 smaller connectors rather than 2 large ones. Hopefully I can sell the one I have and pick up the correct one easily enough.

I started to re-pin the harness as well based on the info from the LT1 swap site which is excellent.






I got some parts to do the rebuild on the transmission. I've done a lot of these 4L60/700r4 transmissions now... some minor upgrades while it's out to HEG frictions, a better band, steel apply pistons and a HD2 shift kit. All of which should make it live much longer. Besides I need to tear it down to change the output shaft so I can keep the 4wd.



All of the extra wires have been traced and removed. All that's left to do is put in the wires for TPS and IAC as I converted from DBW to cable throttle.

The connectors for the transmission range switch are damaged, but I should be able to replace them easily enough.

06-09-16, 07:33 PM
A pretty straightforward job, just needed a bit of patience. I just worked on one circuit at a time and labelled cables as I went, as there are a lot which are the same color....





I then spent an hour working on the motor, starting to strip it down for inspection and rebuild. I know it's had water in it, so I'm going to tear it down completely.

Removing the fan and clutch wasn't easy. I ended up making a holding tool from some flat stock that I bolted to the holes in the front of the water pump pulley, then used my largest adjustable wrench and a large hammer to undo it.

Removed the intake. Need to swap the throttle body for a cable one if I can find one.

The EVAP/purge solenoid is broken, but I won't be using it anyway.




Finished wrapping up the harness. Just a couple of pieces to finish, but I'll leave those until it's in the truck and I know exactly where everything needs to be.


I also made a start on tearing down the motor. It's certainly been stood outside uncovered at some point. Haven't got as far as pulling the oil pan yet, but hopefully will do that tomorrow and see if there's any damage. Hopefully there won't be! Looks ok so far with the exception of some very minor pitting in one bore, which I hope will hone out.

Tearing it down does at least mean I get to be 100% happy that everything is good and there won't be any surprises down the line :)


08-09-16, 07:48 PM
I stripped the rest of the motor down tonight, just the crank and cam to remove now, but the hardest part is done. Getting the crank pulley off. The bolt is done up FT... and the pulley is a press fit on the crank snout at well. Hard to get a puller on it unless you have the special tools, which are hard to find in the UK.

But a lump of wood to jam the crank while cracking the bolt free and a lightly modified puller made getting it off reasonably easy....

I'll get the crank and cam out over the weekend and the block cleaned, measured and checked before honing the cylinders and getting it ready for rebuild.



08-09-16, 08:56 PM
I love a bit of old school engineering:tup:
Just had to make an inner tie rod removal tool for one of the daughters new shape VW beetle, a piece of scaffold tube a large sledge hammer a couple of drill bits 8mm tap and an old bolt works a treat.

10-09-16, 07:09 PM
Thanks :) I normally find a way around things...

I've given up on the motor for the time being as it needs a rebore.

Plus it's been raining hard all day today so I decided to get the transmission rebuilt. I needed to strip it down to fit the 4wd output shaft anyway. Pulled the pan off and found it was full of clutch material. Turned out there were 2 toasted clutch packs and one check ball wedged firmly in the separator plate. I expect that was a contributing factor.... Aside from that I couldn't find any major issues with it other than the normal wear you would expect.

HEG frictions throughout including 3-4 powerpack (1 extra steel and friction), alto red eagle band, corvette servo, Transgo HD2 shift kit then new seals and stuff throughout. Should all help it live for a long time in my truck as it will mainly be towing :)










10-09-16, 08:39 PM
How's my bike doing?

11-09-16, 07:31 PM
Lol, should be SVA'd over the winter and on the road next spring :)

19-11-16, 08:11 PM
Washed the intake manifold out with some old fuel to clean all the old oil and gunk out of it. Then got the billet cable throttle fitted up. I gave the injectors a soak in my ultrasonic cleaner and they now look like new again. I'll refit them with new seals soon.

I also got the crank removed from the block, main bearings and crank are perfect. Just need to get the block bored and honed then I can get it built back up again.