8x Series V8 Swaps (13 Viewers)

[thatcabledude]

Good to know

Since you have some experience with these, would you have any concerns with the reliability of the Holley system versus an OEM PCM? Also wondering if I'd be able to tune for MPG and/or pass emissions, since they're geared more toward enthusiasts.

The harnesses are plenty nice. I'm just a stickler for tidiness. As far as tuning for emissions and such I don't have a clue. Thankfully emissions testing and inspections aren't something I've ever had to experience.

I'd assume aftermarket ECMs were an automatic fail. I've never looked into that.

 

[Joe Link]

The harnesses are plenty nice. I'm just a stickler for tidiness. As far as tuning for emissions and such I don't have a clue. Thankfully emissions testing and inspections aren't something I've ever had to experience.

I'd assume aftermarket ECMs were an automatic fail. I've never looked into that.

That's definitely something I'll have to look into. Thankfully, they aren't too strict here in Oregon.

 

[White Stripe]

What kind if average did you see on your old setup?

11 or 12. I never got a chance to pursue a better tune for it.

 

[Joe Link]

Did any of you LS guys regear? If so, what transmission and what tire size are you running?

Planning on running 35's-37's, I went to 4.88's before I decided to swap and I'm worried I'm going to regret it.

 

[thatcabledude]

Did any of you LS guys regear? If so, what transmission and what tire size are you running?

Planning on running 35's-37's, I went to 4.88's before I decided to swap and I'm worried I'm going to regret it.

I ran stock gears and 315s with 4l60e for 3 years. Absolutely, totally fine for me. Yes, I live in FL, but I’ve driven/wheeled the truck in CO, UT, etc.

I switched to 37s a few months ago and the truck drove great and I didn’t notice much of a change in acceleration on the street after the bump in tire size, but had not wheeled it yet. Felt good on the interstate and the 1,800ish RPMs at 60mph was nice too. My rear diff was in dire need of rebuilding and I figured I may as well regear. I went 4.88s. I’ll be plugging the 3rds in this Wednesday, so I will be able to let you know what I think really soon.

 

[Joe Link]

I ran stock gears and 315s with 4l60e for 3 years. Absolutely, totally fine for me. Yes, I live in FL, but I’ve driven/wheeled the truck in CO, UT, etc.

I switched to 37s a few months ago and the truck drove great and I didn’t notice much of a change in acceleration on the street after the bump in tire size, but had not wheeled it yet. Felt good on the interstate and the 1,800ish RPMs at 60mph was nice too. My rear diff was in dire need of rebuilding and I figured I may as well regear. I went 4.88s. I’ll be plugging the 3rds in this Wednesday, so I will be able to let you know what I think really soon.

Perfect!

 

[ajordan1975]

Did any of you LS guys regear? If so, what transmission and what tire size are you running?

Planning on running 35's-37's, I went to 4.88's before I decided to swap and I'm worried I'm going to regret it.

I’m on 37’s and 5.29’s w/ a 4l60. It’s a little over geared, but I’m happy w/ it. I live in Colorado and it’s nice pulling passes w/ ease.

 

[goranvolvo]

Did any of you LS guys regear? If so, what transmission and what tire size are you running?

Planning on running 35's-37's, I went to 4.88's before I decided to swap and I'm worried I'm going to regret it.

i did same thing i swapped to 4.88 before engine swap and just left it in i run 5.3 LS with 4l60 on 35 " tires it runs on higher rpm but you can feel the torque especially off the road and i m leaving it in

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[Cruiserhead05]

I'm running 4.88's, 37's and 6L80e. It's great.

RPM's at 70mph are right around 2100 and speedo is almost dead on.

edit: would be curious what others are seeing for cruising revs. I've been tempted by the 10% high range overdrive to further drop my revs for highway cruising.

 

[Atwalz]

Step one is done. Parts are tricking in for LS3 erod connect and cruise 6.2L crate motor paired with 6L80E.

 

[Cruiserhead05]

Pretty sure you'll never go back.

 

[Tinkertoy]

Step one is done. Parts are tricking in for LS3 erod connect and cruise 6.2L crate motor paired with 6L80E.

View attachment 2666594

Sorry for the dumb question. Are you planning to use a Narks adapter or go a diff route?
I have a L96 with a 6L90 coming and curious of my options.

 

[Atwalz]

Sorry for the dumb question. Are you planning to use a Narks adapter or go a diff route?
I have a L96 with a 6L90 coming and curious of my options.

Mark’s 4wd adapter

 

[cme4lyt]

Sorry for the dumb question. Are you planning to use a Narks adapter or go a diff route?
I have a L96 with a 6L90 coming and curious of my options.

I‘m guessing he’s using a Marks adapter; I heard the Narks are discontinued

 

[Feldrian]

I‘m guessing he’s using a Marks adapter; I heard the Narks are discontinued

I have a Narks for sale. Mail me $400 cash and I'll send it to you. NEW IN BOX!

 

[labrynth20]

What is the thinking about the 6 speed automatic vs the 4 speed? Are they roughly the same size or does one take more work under the beast to get the 6 speed to fit?

 

[Tinkertoy]

I have a Narks for sale. Mail me $400 cash and I'll send it to you. NEW IN BOX!

I was gonna get the Narks 2000. I hear it adds 15HP to the wheel.

 

[White Stripe]

Here is some of my feedback of a 5.3 vs a 6.0. Hope it helps others. My 80 had a stock lm7 with a performance tune. I just swapped in a 6.0. Got my 6.0 with stage 2 truck cam and ported heads locally tuned.(technically it's a 6.1 after the rebuild)It still needs a little tweaking. Fuel mileage already seems better than the 5.3 with the mail order tune. But I need to start a fresh tank to figure mileage. I towed my 3500 lb camper and it's a much better drive with the 6.0. I stayed in the fast lane without much effort. I didn't do any mountain passes yet. The 5.3 did it ok, you could definitely feel the camper back there and had to keep the rpms up more, but the 5.3 is bullet proof and it doesn't mind. I only lost 1mpg towing my camper over mountain passes giving it all she had. After driving the 6.0 around unloaded I have mixed feelings. Is it a rocket ship? No. I am a little disappointed actually in the acceleration actually. I was expecting a huge difference. I am kind of jaded though because I drive quite a few forced induction cars and trucks fairly often. Will it beat a eco boost f150 unloaded? I'm not sure. I think the eco boost would win. If so oh well. A higher stall converter would increase acceleration significantly but there are some negatives to that.

Back to towing with the camper: With the additional torque of the 6.0, it really didn't accelerate much slower at all through first and second gear with the trailer compared to unloaded which is really impressive. 3rd gear is when you notice it's slower with the camper. But I was able to keep 80 or more in od. In fact I have no doubts it could cruise 90mph with the trailer if I wanted. When I tried to accelerate at 75 or so it would drop to 3rd, get to 80 or 85 without trouble, then go to od and cruise along happily. The torque shines here. I also wired up the tow haul switch and that's really nice with the trailer. This current setup is probably about perfect for most people to be really happy. While it will cruise really well with the trailer, a 80 series with a offroad camper doesn't corner well and I had to be careful to not drive like I'm unloaded-the 6.0 would try if I let it. Im glad my suspension only has only a mild lift in this case.

Could I use more power? Always...unless we're talking 700hp or so, that would just get too out of hand. I would say perfect for me would be a 408 stroker. The machine shop talked me out of it. I think that's what I should have done. Or maybe supercharge or turbo the 5.3 but forced induction creates more complexity than I am not really wanting to take most days. But looking back, I would probably have just put a lsa supercharger on the 5.3 just because it's bolt on almost. I didn't realize the snowball of camming the 5.3 monetarily at the time. Basically it started off I just wanted to cam the 5.3 for a little more power. Then I started to think-well if I do that, I gotta either pull the motor, or rip the front end apart. If I do that, I may as well just drop a used 6.0 in and sell the 5.3. So I bought a 6.0 with decent mileage for 1300. I could sell the 5.3 for at least 500, and have a 6.0 for 800 or so. The 6.0 puts out much better torque stock than a cammed 5.3. I decided to pull the heads and inspect the 6.0. It looked normal, but then I thought about how I want to not mess with it again for a long time. So I rebuilt it. Which shot the price overall way up. I probably have 4000 or so all together into the motor with rebuild. Which is about the price of a lsa supercharger kit for a 5.3. Which would give more power than a cammed 6.0 but have additional complexity. Thus why I'm thinking a 408 would be perfect. A 408 is a 6.0 with a stroker crank shaft fyi. It ends up taking the 6.0 360ci engine to a 408ci 6.8 liter engine which would be way more torque. I also could have dropped in a 8.1 but I would need more suspension lift, significant hood mods to fit it. And I don't think emissions laws in my area would allow a 8.1 swap. Anyway cruiser is fine, it's great, it could be more, but I'm not planning on changing it. And I got about 70 or 80hp over the 5.3 and about the same 70 or so more torque over the 5.3. The torque curve is really flat which is good for a cruiser.

 

[EricG]

I always get 15 with city driving. And I get on it a a lot. I don’t know how much the truck weighs, but front and rear bumpers full spare, sliders, etc

What size tires are you running?

 

[thatcabledude]

What size tires are you running?

315/70r17 until recently changing to 37/12.5. No noticeable change between the two really.

I’ve changed to 4.88 and am running through the first full tank now so I don’t know what it will be now. I’ll report back at some point.