5.3L retrofit advice

[ImpalaSam]

OK, here's the deal 5.3L truck motor with ecu, harness and accessories for $850 or $650 w/o harness and ecu.
What are the pros and cons of using the factory ecu vs MS. This would be my first efi retrofit so take that into
account. I see this as being a stock swap for now but I would like to be able to "grow" as far as the power
goes maybe starting with a cam swap, headers and progressing to a turbo. I see the love for the MS here
but is it always the best route?

[shaun callaway]

Re: 5.3L retrofit advice

personally speaking it would be better for the long run if you plan on going turbo.

with the stock pcm you have to get hp tuners or something to be able to modify tables and i would not suggest that for a novice.

the ms community is far greater than the hp tuner community.

[squirrel]

Re: 5.3L retrofit advice

One bonus of getting it with the harness/cpu is that you have a harness, so you can wire up the electronics to the MS more easily.

Two bills might be a bit expensive for it though.

[BangShiftChad]

Re: 5.3L retrofit advice

What is it going into?

I'd go MS or EMS Pro myself. Energy Suspension just came out with adapter plates, hardware, and new poly mounts to put the LS in a lot of stuff. Details are coming in a new product blog.

[ImpalaSam]

Re: 5.3L retrofit advice


It's going in my '65 Impala. The stuff from Energy sounds interesting. I've been trying to do some research on what all would be involved using the MS. The software to tune the stock ECU is not cheap so I don't think I'll be saving a whole lot of dough going that route. I still need info on what ignition to use, if I go with the MSD stand alone driver that will add to the expense but I don't know enough about the MS yet to see what my other options are. I also have some questions about the engine placement with some of the adapter mounts. I will be using a 4 speed with mechanical linkage and with the Impala it uses the hole that is on the bellhousing so I may run into some alignment issues. Still have a lot of homework to do before I dive in. Keep the feedback coming!

[Caveman]

Re: 5.3L retrofit advice

We started to do this on my buddies' '65 Impala... we hit a lot of snags, which is why he didn't finish it, and how I ended up with the car.

Snag #1: The oil pan WILL hit the crossmember when using the square adapter plates. Not sure what the original vehicle application his LS swap motor was from, but the oil pan that was on it didn't stick down very far, maybe 2-3 inches. The adapter plates he had were the 3/8' thick steel rectangular pieces (about 3"x4" ish) that allow you to use a regular SBC motor mount. I'm not sure what company he ordered from. The motor ended up sitting on the crossmember, keeping the engine about 1/2" too high to get a bolt through the mount. You'll have to either notch the crossmember, or find a custom oil pan.

Snag #2: The adapter mounting plates don't locate the engine EXACTLY the same spot as an SBC, front to back. It's either touching the firewall (which wasn't far enough back to make the motor mounts line up), or its too far forward. We swapped the adapter plates from side to side trying to change the forward/rearward location, and it worked, moving the engine about 4" forward... which made the situation with the oilpan even worse, plus there was a huge gap between the engine and firewall.

Bottom line: research the heck out of whatever mounting kit you get. CALL the company, and ask them if it will make everything fit in your Impala. If the sales guy says "ya, sure it'll fit" ask him to prove it. Better yet, ask them how many kits have been installed into a '65 Impala, and what the feedback was. If your salesman doesn't know, or can't get a tech guy to answer the questions directly, shop somewhere else.

As far as the EFI stuff goes, these guys are NASA & they love to help, so you should do okay.

FYI, I still have a DiabloSport Tuner from my buddies 6.0 LS project, and I'll give you a sweet deal on it if you want. Its never been used, seriously.

[ImpalaSam]

Re: 5.3L retrofit advice


Thanks for the input! I had heard that the motor mount adapter plates can cause issues so I am definitely doing some homework. BRP Hotrods has a different type mount that I have been looking at but they don't list a "65 Impala. It appears their kits use a LH8 oil pan which is from a H3/Canyon with the V8, that could be the key to getting it all to fit.

As for the electronics, the more I read the more intimidated I get. I have a good understanding of EFI from my GN, but tweaking a factory system and building one from scratch is a little scary. My main concern is not so much tuning it once I get it running but trying to do it all and keep an eye on the budget. I just don't want to start off in one direction and then have a ton of suprise expenses derail the project.

I still have a lot to do on the car so I am not going to rush it.

[Caveman]

Re: 5.3L retrofit advice

Yeah, the pan is the key. I'd try to look at one of the H3 pans side by side with a truck pan, and maybe a vette pan... most clearance wins!

Are you re-doing the motor, or just gonna stab it in?

[ImpalaSam]

Re: 5.3L retrofit advice


I plan on just "dropping it in" which I hope will be the easy part. I am still if recon mode for now trying to get all the information I can before spending the cash. I have been busy this week so not a lot of time for research. Ultimately I would like to add a turbo but for now I think just getting one in and running stock would be a more realistic goal.

[Caveman]

Re: 5.3L retrofit advice

A stock 5.3L with a good cam should be pretty darn strong. Most of the magazine builds on these are 6.0-based, but a 5.3 should still make pretty good power with just a cam change.

Try Advance Adapters for the flywheel... they make tons of 4x4 engine swap stuff, so they should have some of the things you'd need.

[ImpalaSam]

Re: 5.3L retrofit advice


Did some checking into my options with MS for a 5.3.

The fueling issue seems pretty straightforward but the ignition end not so much. From what I have found my options
look like this:

MSD standalone for ls1 $320.00

Ford EDIS8 for $120.00

It appears the MSD would be the easiest but a little more money and the ignition curve is not controlled with the MS, correct?

With the Ford the MS controls the ignition but there are some hurdles with mounting the 36-1 wheel and pickup but it is less expensive.

Is there no way for the MS to control the ignition using the stock 5.3 coils and factory crank wheel or is it just a hassle and no one does it.

[LS1 ZR2]

Re: 5.3L retrofit advice

Why not build the car using the original (modified) harness and ECM? In the future if you chose to modify it beyond the capability of the production controller, change it then.

All you have to do to the ECM to make it run is to turn off theft. Plus, if you chose to run the 4L60E trans it will control it as well. We do a number of LS based swaps at me shop, and we almost always use the production controller.

[ImpalaSam]

Re: 5.3L retrofit advice


I have not ruled out using the factory ecm, I am just trying to determine which route would be best as far as price, future mods and initial start up issues.

The price I got on the engine would include the harness and ecm for an extra $200.00. Looking at software it looks like another $500 for that but there would be no additional cash outlay for the ignition.

One option that I have not had a chance to check on would be to get the factory ecm and get someone to turn off the theft in it since the engine would be stock to begin with. Obviously there would be a charge but it might be the least expensive route.

Also, I will be using a manual transmission and I don't know what mods would need to be made to the harness/ecm to get that to work or even if it could be done.

I have some experience with EFI but a swap into an older car is new to me so any advice/information is appreciated.
Everyone has opinions based on their experience and there is not necessarily one "right" way to do this.

[greenjunk]

Re: 5.3L retrofit advice

there should be no anti theft on a truck ecu of that era.
the computer and harness is worth more than $200. I would believe it would be easier to wire any aftermarket computer with the factory harness already wired.