All too common LS swap vs unique old school small block

[LOWCREW]

Definitely go LS swap. My son just did one in his '98. Originally a 4.3 5spd NV3500 truck. Then someone swapped it for a 5.7 vortec. Now that he own it he went 5.3 LS kept the 5spd NV3500.

 

[PedroC]

The LS swap is just the most cost effective swap out there. They're cheap, parts are cheap, etc.

If you really want to be unique, keep the V6 LOL.

I’ll correct you there. Any 454 is the most cost effective swap for a GMT400. You don’t need a controller for coils near plug, don’t need any fuel system upgrades and it’s a direct bolt in and a gen6 is more power then any LS that’s not a 6.0 or something with an LSA and big money. Now the V6 and something to push air into it I’m in total agreement for, I would get something to replace it sitting around then a turbo and send it.

 

[Tommy1234]

If money is not a factor and you really want to go unique I would say A GMC 702 V12.

 

[Tommy1234]

Or the 6 cylinder variety of the V12I believe it's A 305

 

[0xDEADBEEF]

I’ll correct you there. Any 454 is the most cost effective swap for a GMT400. You don’t need a controller for coils near plug, don’t need any fuel system upgrades and it’s a direct bolt in and a gen6 is more power then any LS that’s not a 6.0 or something with an LSA and big money. Now the V6 and something to push air into it I’m in total agreement for, I would get something to replace it sitting around then a turbo and send it.

The Mk VI 454 made ~290 hp. That's 4.8-5.3 territory easily.

Sure you can build them, but so can the LS and I don't think you can beat the price of an LS cam swap and springs. I seem to recall the 7.4 needs some head work for any serious cam lift.

 

[L31MaxExpress]

I kept the stock intake, ported the hell out of it, went to a 48 lb/hr spider and P59 swapped my 97 Express. Built a NASTY 383. Should have gone with a Dart SHP 4.125" bore, 350 main, 1-piece rear seal, factory roller compatible block and built a 427. The 383 is a 500+ hp engine and over 500 tq the way it sits and that is without spinning it higher than 5,500. Loads of torque.

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[L31MaxExpress]

The Mk VI 454 made ~290 hp. That's 4.8-5.3 territory easily.

Sure you can build them, but so can the LS and I don't think you can beat the price of an LS cam swap and springs. I seem to recall the 7.4 needs some head work for any serious cam lift.

4.8s and 5.3s are DOGS all noise and no real power NA, stock 350 Vortec has more power. Not even a fan of a 6.0L to be honest. I did heads and cam on a LQ4 because I had one that was low mileage, makes for a reliable cruiser but nothing earth shattering. Stock 8.1 with a 425 hp marine cam and headers that is in my 99 Tahoe has way more balls than any of those including the worked over 6.0L. Only way a LS makes sense is to boost one. Then again working over and swapping in a 250K mile engine is not my idea of a reliable driver. I wanted something basically new from the oil pan up which is why I built my 383. 383 has a ton of grunt from off-idle to 6,200 rpm.

My Tahoe 8.1 never ceases to amaze me power wise. Its quiet and just pulls that Tahoe around with ease. Stock small block converter in the 4L80E and 3.42s with 32" tall P305/50R20s. It jumps off the line despite the tall gearing and by the time it is at 5,200 rpm its rolling almost 60 mph. By the time it goes to grab 3rd its rolling almost 100 mph. As long as the go pedal is down it keeps pulling. Stood on it from a very slow roll, headed up a short uphill ramp and looked down at the top and was already running almost 100 mph with 1 shift! It makes like 450 hp at 5,100 rpm but over 550 tq at 3,600 rpm. Makes as much torque off-idle as a cammed 6.0L does at peak at 4,000+ rpm. The 8.1 effortlessly cruises 70 mph at a mere ~1,800 rpm returning 17-18 mpg. In normal driving it is in lean cruise at 30 mph and will accelerate in overdrive easily at 40 mph with the torque converter locked without leaving lean cruise. It just barely has to work to move the Tahoe with authority.

Stock 8.1 with 7 psi of boost made 850 ft/lbs of tire shredding torque on Westechs dyno after Richard Holdner strapped it to the dyno.

 

[PedroC]

The Mk VI 454 made ~290 hp. That's 4.8-5.3 territory easily.

Sure you can build them, but so can the LS and I don't think you can beat the price of an LS cam swap and springs. I seem to recall the 7.4 needs some head work for an

The Gen6 is 410 Ft-lb of toque and 290 Hp in stock form but the toque starts at 1800 rpm. You don’t need a huge lift the heads are capable of enough power to get yourself in trouble of you want a cam swap you should change valve springs. The LS is the new Big Block, when you wanted power a 454 from a truck at the wrecking yard was the answer forever.

 

[0xDEADBEEF]

4.8s and 5.3s are DOGS all noise and no real power NA, stock 350 Vortec has more power.

Factory HP ratings say otherwise.

 

[0xDEADBEEF]

The Gen6 is 410 Ft-lb of toque and 290 Hp in stock form but the toque starts at 1800 rpm. You don’t need a huge lift the heads are capable of enough power to get yourself in trouble of you want a cam swap you should change valve springs. The LS is the new Big Block, when you wanted power a 454 from a truck at the wrecking yard was the answer forever.

But we're talking about the present. There's just way more LS truck motors at the junkyard, and the aftermarket support is better. I watched a Richard Holdener video last night where he dyno'd 20 different LS intake manifolds. 20! Maybe there are 20 different Mk 6 BBC intakes out there, I don't know, but I doubt it and they aren't as easy to get.