LT1 vs. Vortec vs. LSx

[81chevys]

If you can swing the initail cost of the 5.3 or 6.0 (gas no diesel) then go for it. Mileage would consideralbly pick up and so will the power. Several people with ls setups in our trucks getting 23-25mpg with little effort. and if you ever decide to step it up the aftermarket is great.

[jb1016]

^ I think that's the biggest strike against the LT motors (LT1/LT4): They didn't make them for long, and hardly anybody is transplanting them anymore, meaning it's gonna get tougher in the future to find aftermarket support for them.

LS swaps are great. But you have to have a whole lot of cash up front, or a great shop to work out of and tons of time and fab skills. I DD my truck, and I'm wanting to go to Vortec heads and modify my factory TBI. (The GMPP intake really is pricey; I'd probably do a carb intake with an TB adapter.) A little cam, headers, tune, more fuel and better ignition should make a nice everyday cruiser. Would the mileage savings make a 5.3 swap worth the extra money? Probably, but I don't have the money on the front end, so it doesn't matter

[BigBlocksRule]

Originally Posted by 81chevys

If you can swing the initail cost of the 5.3 or 6.0 (gas no diesel) then go for it. Mileage would consideralbly pick up and so will the power. Several people with ls setups in our trucks getting 23-25mpg with little effort. and if you ever decide to step it up the aftermarket is great.

If you don't mind, I'm gonna hang around and wait for some of these guys getting 23 - 25 mpg with a square body and any LS engine.
They get around 10% - 15% better fuel economy than a conventional small block. They're great engines and all, but they're not magic. They just do a better job of getting fuel and air into the engine than the older stuff.

[kevinr1970]

Originally Posted by jb1016

LS swaps are great. But you have to have a whole lot of cash up front, or a great shop to work out of and tons of time and fab skills.

Aren't pretty much all the mounts available through SLP or S&P(?); what kind of fab work is required?
Unfortunately I don't have the patience to work through issues like that, I prefer the bolt in aspect even if it is a little pricier.

Originally Posted by jb1016

...I'm wanting to go to Vortec heads and modify my factory TBI. (The GMPP intake really is pricey; I'd probably do a carb intake with an TB adapter.)

Is this a realistic option?
For my '87 crew (TBI) the engine is very tired (166k); it shows about 40psi at start up, but is around 0 after I get it warmed up. I am sure the gauge is off or it would be making some serious noise, but it smokes on start up (blue) and I think I can see blue smoke when I get on it.
The 3.73's with a T400 and 275/60-15's aren't helping either when I insist on going 70mph on the freeway.
I have a low mile 350 in my garage and I had planned on putting that engine in my '87 with a EGR Edelbrock Performer manifold with a TBI adapter. If the Vortec heads are that much better it might be worth the work you described above?

Originally Posted by BigBlocksRule

If you don't mind, I'm gonna hang around and wait for some of these guys getting 23 - 25 mpg with a square body and any LS engine.
They get around 10% - 15% better fuel economy than a conventional small block. They're great engines and all, but they're not magic. They just do a better job of getting fuel and air into the engine than the older stuff.

I am not sure about the squares, but in my '06 GMC reg cab swb with a 4.8 v8, 5-speed manual and 3.23's with a tune I got a best of almost 24 going through eastern Oregon. That included one section where I passed a clusterf* of RV's, campers and tractor trailers on a section with great visibility and was going almost double the speed limit...

[81chevys]

Well i cant tell you about your oil problem but ive seen it done on a tbi truck with a performer for vortec heads. It worked and made decent power. They used the used a spacer. No need for the gmpp

Also therebare ls setups that do get 23+mpg. They generally are not lifted but they do exist. My truck weighs 3990 with the sbc iron heads and iron intake. The ls is a hare lighter with the plastic intake and aluminum heads. I expect at least 20mpg
Posted via Mobile Device

[clinebarger]

My 85 5.3L 3/4 ton Suburban gets 17-19MPG, My 04 5.3L 1/2 ton Crew gets 13-17MPG. The Suburban has a tune & will out-run my Crew & gets better mileage....Same Engine/Trans/Gears & similar weight & tire height, The tune makes alot of difference.

I have got mid twenties out of a 00 Pontiac Trans Am LS1/M6 stock with a good tune. I highly doubt you can get that with square body brick.

[jb1016]

kevinr, I may be wrong, but that's the impression I've gotten from following LS builds on here. You can probably get by without any fabrication, but I'm betting if you have some skills you'd be able to save some cash.

And from everything I've ever heard, the Vortecs are light years ahead of the factory TBI heads, which flow pretty badly.

[travis401]

Originally Posted by kevinr1970

Originally Posted by jb1016 View Post
...I'm wanting to go to Vortec heads and modify my factory TBI. (The GMPP intake really is pricey; I'd probably do a carb intake with an TB adapter.)

Is this a realistic option?
For my '87 crew (TBI) the engine is very tired (166k); it shows about 40psi at start up, but is around 0 after I get it warmed up. I am sure the gauge is off or it would be making some serious noise, but it smokes on start up (blue) and I think I can see blue smoke when I get on it.
The 3.73's with a T400 and 275/60-15's aren't helping either when I insist on going 70mph on the freeway.
I have a low mile 350 in my garage and I had planned on putting that engine in my '87 with a EGR Edelbrock Performer manifold with a TBI adapter. If the Vortec heads are that much better it might be worth the work you described above?

its definitely a realistic option. its only as difficult as a head swap and and intake swap. the thing with the vortec heads is they flow GREAT at low lift. so you dont need a high lift cam to get decent power out of it. the L31 ( the vortec headed truck engine) made as much as 230hp/330tq with a small lift cam. theyre a 64cc head, so you need to make sure the pistons you use/have wont push the compression ratio up to high.

[stroker87]

Dont do what I did (TPI 350) I dropped a ton of money and time to get the power out of it and in the long run it would of cost less to do a 5.3 swap and have more power for less money my engine stock had 210hp(TPI 350) when I was done it made 300hp @ the wheels the 5.3's start around 300hp+ (flywheel) but with tuning and simple bolt on's you can get an easy 60 to 70hp more

I didnt cheap out on my engine stealth ram injection, forged internals, splayed caps, aluminum heads & Etc. $10k invested and just redone it for more power another $3k way deep in it!

a 5.3 with the same HP would of cost about 1/2 as much! when I was shopping for an engine 4 years ago the 5.3 aftermarket was just taking off and every thing was very hi cost now its cheaper to do and with the conversion kits made easy not to mention how many 5.3's you see out there with over 150k miles on them getting 15mpg+ but the down fall is all the electronics the air intake tube on my 07 suburban fell off and true a engine code and the truck was not shifting right lol

[kevinr1970]

Originally Posted by travis401

its definitely a realistic option. its only as difficult as a head swap and and intake swap. the thing with the vortec heads is they flow GREAT at low lift. so you dont need a high lift cam to get decent power out of it. the L31 ( the vortec headed truck engine) made as much as 230hp/330tq with a small lift cam. theyre a 64cc head, so you need to make sure the pistons you use/have wont push the compression ratio up to high.

The eninge was rebuilt by the previous owner of a truck I no longer have so I don't really know much about it, except it was rebuilt as stock but with an "RV" cam.
I ran pump regular gas on it with no problems

Originally Posted by stroker87

Dont do what I did (TPI 350) I dropped a ton of money and time to get the power out of it and in the long run it would of cost less to do a 5.3 swap and have more power for less money my engine stock had 210hp(TPI 350) when I was done it made 300hp @ the wheels the 5.3's start around 300hp+ (flywheel) but with tuning and simple bolt on's you can get an easy 60 to 70hp more

I didnt cheap out on my engine stealth ram injection, forged internals, splayed caps, aluminum heads & Etc. $10k invested and just redone it for more power another $3k way deep in it!

a 5.3 with the same HP would of cost about 1/2 as much! when I was shopping for an engine 4 years ago the 5.3 aftermarket was just taking off and every thing was very hi cost now its cheaper to do and with the conversion kits made easy not to mention how many 5.3's you see out there with over 150k miles on them getting 15mpg+ but the down fall is all the electronics the air intake tube on my 07 suburban fell off and true a engine code and the truck was not shifting right lol

My goal is stock with bolt on/tuning so maybe I need to reconsider that LSx option...

[meter swinger]

I just ran across an add here in richland on CL. Can't post link from phone though. The add reads;
"6.0L LQ4 OUT OF 2500 TRUCK. HAS 60K MI. 509-539-2973 /WARRANTY."
May be worth a phone call, and with the hanford layoffs hurting the economy he may not be all that firm on the price.

The add is a couple pages back under parts KPR Craigslist and has pics.
Posted via Mobile Device