LS3 Crate Engine Swap
Thread Starter
Teching In
Joined: Feb 2019
Posts: 11
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LS3 Crate Engine Swap Hi,
I’m about to purchase and install a 427 LS3 crate engine into my 69 Camaro. The engine comes with a GM harness. My 69 Camaro currently has a SBC 383, T56M with a Silversport Trans X-member, Ridetech with Tru-Turn and 4-link, and no tunnel mods. This is my first LS swap, I've done a lot or research, but I still have a few questions before I get started. I’m trying to control the cost of peripheral parts creep as much as I can.
I’m about to purchase and install a 427 LS3 crate engine into my 69 Camaro. The engine comes with a GM harness. My 69 Camaro currently has a SBC 383, T56M with a Silversport Trans X-member, Ridetech with Tru-Turn and 4-link, and no tunnel mods. This is my first LS swap, I've done a lot or research, but I still have a few questions before I get started. I’m trying to control the cost of peripheral parts creep as much as I can.
- Silversport is recommending flywheel 460530. Are there cheaper similar quality flywheels out there?
- Do I need an oil catch can for this engine?
- Will the Holley Blackheart motor mounts work with SST’s trans x-member or do I need to get the Holley x-member as well? It was suggested to get adjustable mounts because the SST member already located the trans in the original location and length of driveshaft. But I've heard the Holley kit lowers the engine and makes everything fit perfectly and without tunnel mods.
- How many are using the PCM vs an external fuel pressure regulator? Which is better and why? If I need to run an external regulator which is better to use, BYP7910-KIT or AFPR1.
- Is there a quality 302-2 oil pan out there other than the $500 Holley version. I see them online for $150 or so.
- Where/How is everyone running the wiring harness? I wanted to put the ecu in passenger wheel well behind the head light. I don't know how long the harness is or its layout.
1) Looks like a standard LS flat flywheel
2) No
3) Typically, you want to match brands
4) I assume you mean fuel module vs fuel regulator
Most swaps will go for the regulator because it's less complex, easier to diagnose and has tons of aftermarket
Which regulator isn't critical. It needs to have a 40-70psi range. That's about it
5) The knock off pans are most likely cast in the same factories as the actual holleys. They have QC issues, but nothing critical
6) For the best fitment, have one built specific to the car. Baring that, order a stand alone
The GMPP harness leaves ALOT to be desired in addition to a unique E67 pinout
Since you already have it, drape it over the engine to get a rough idea for ECM/fusebox placement
I recommend ditching the GMPP wiring and going holley terminator x max, but that's my opinion
2) No
3) Typically, you want to match brands
4) I assume you mean fuel module vs fuel regulator
Most swaps will go for the regulator because it's less complex, easier to diagnose and has tons of aftermarket
Which regulator isn't critical. It needs to have a 40-70psi range. That's about it
5) The knock off pans are most likely cast in the same factories as the actual holleys. They have QC issues, but nothing critical
6) For the best fitment, have one built specific to the car. Baring that, order a stand alone
The GMPP harness leaves ALOT to be desired in addition to a unique E67 pinout
Since you already have it, drape it over the engine to get a rough idea for ECM/fusebox placement
I recommend ditching the GMPP wiring and going holley terminator x max, but that's my opinion
TECH Senior Member
Joined: Jul 2009
Posts: 8,034
Likes: 664
The GM ECU requires someone to tune it after mods. The Terminator X is self tuning while still letting novices and pros to fine tune it to meet your requirements.
You should be happy Holley has this out now. It’s a nice setup
You should be happy Holley has this out now. It’s a nice setup
On The Tree
Joined: Mar 2010
Posts: 122
Likes: 36
Unless you are planning big upgrades in the future I would stick to the GM computer. I've been involved with 2 kits using basic intake tubes & Holley exhaust manifolds. Started right up & ran great.
You get proven 100k mile reliability in the computer. Even if you have to get tuned at some point you are still cheaper than the Holley.
You get proven 100k mile reliability in the computer. Even if you have to get tuned at some point you are still cheaper than the Holley.
Thread Starter
Teching In
Joined: Feb 2019
Posts: 11
Likes: 0
I believe the ECU is already tuned for the engine. The car is complete with the exception of body and paint which currently sits at a 6.5/7 out 10. The engine is 625HP/555TQ, so I don’t have any plans for mods or upgrades there.
Will be replacing entire exhaust that was just built last year and get bigger tires are my next “mods”.
May be a dumb question, but can you program GM ECU to set a rev limiter?
Will be replacing entire exhaust that was just built last year and get bigger tires are my next “mods”.
May be a dumb question, but can you program GM ECU to set a rev limiter?
