Engine help

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nickknox

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1987
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c30
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6.2
Hey everyone,

I’m looking for suggestions for my ‘87 c30 crew cab 2wd. It’s a great truck with a smooth ride. I’m looking to turn it into a road trip truck and eventually pull a 5th wheel RV.

It has a 6.2 Detroit in it. It’s fine, but not exactly the engine for pulling. I’d love to put an LBZ into it and I know it’s been done. I just don’t know how much goes into that swap. I don’t need a 600hp monster, I mean I’d love it, but I don’t need it.

So if you were in my boat, looking at long road trips and eventual RV pulling what engine/transmission would you put in? I’m open to suggestions?
 

AuroraGirl

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400(?), 350
Hey everyone,

I’m looking for suggestions for my ‘87 c30 crew cab 2wd. It’s a great truck with a smooth ride. I’m looking to turn it into a road trip truck and eventually pull a 5th wheel RV.

It has a 6.2 Detroit in it. It’s fine, but not exactly the engine for pulling. I’d love to put an LBZ into it and I know it’s been done. I just don’t know how much goes into that swap. I don’t need a 600hp monster, I mean I’d love it, but I don’t need it.

So if you were in my boat, looking at long road trips and eventual RV pulling what engine/transmission would you put in? I’m open to suggestions?
the detroit would be fine for pulling if you went and turboed it or got a 6.5 from the 90s with a turbo

But you could also just do ehst you said, duramax drivetrain.. but you are about to spend your lifes money on that.(They tend to be pricy) So I would recommend if your 6.2 is in good shape, do osmething with it. but if its not, gasoline
 

ByrdDog

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1979
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Chevy
Engine Size
6.2
Could always (Gasp!) go for a cummins swap. I believe 1st & 2nd gen cummins only require 1 wire to run; everything else is mechanical. Will make way more power than the 6.2 ever could. I've pulled with a 6.2/TH400 in a 1 ton & it would do it, just not very fast. On longer hills, not at all uncommon to be doing 25mph in first by the top. If keeping the 6.2 is a consideration, do lots of research on its capabilities. Blocks & heads tend to crack, & they can only take 8-10psi of boost safely. These motors were designed for efficiency, not torque, hence their prevalence in 1/2 ton pickups.
 

AuroraGirl

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Could always (Gasp!) go for a cummins swap. I believe 1st & 2nd gen cummins only require 1 wire to run; everything else is mechanical. Will make way more power than the 6.2 ever could. I've pulled with a 6.2/TH400 in a 1 ton & it would do it, just not very fast. On longer hills, not at all uncommon to be doing 25mph in first by the top. If keeping the 6.2 is a consideration, do lots of research on its capabilities. Blocks & heads tend to crack, & they can only take 8-10psi of boost safely. These motors were designed for efficiency, not torque, hence their prevalence in 1/2 ton pickups.
6 in a row READY TO TOW
 

nickknox

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1987
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c30
Engine Size
6.2
Could always (Gasp!) go for a cummins swap. I believe 1st & 2nd gen cummins only require 1 wire to run; everything else is mechanical. Will make way more power than the 6.2 ever could. I've pulled with a 6.2/TH400 in a 1 ton & it would do it, just not very fast. On longer hills, not at all uncommon to be doing 25mph in first by the top. If keeping the 6.2 is a consideration, do lots of research on its capabilities. Blocks & heads tend to crack, & they can only take 8-10psi of boost safely. These motors were designed for efficiency, not torque, hence their prevalence in 1/2 ton pickups.


Never thought of a Cummins. How involved would that swap be?
 

RanchWelder

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Blazer
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355ci
$18,000 for 24 valve Cummins, rebuilt, without the fuel system and new harness, electrical ignition, etc... The fuel injection system is another $2500.
(Summit Racing).
$35,000 for the Holey Grail Cummins 12 valve, (with the upgrades to prevent early engine failure), same fuel injection cost ^^^.

The 454 would be tough-er to swap into a Diesel rig, in my opinion.
It's cheaper, even after you upgrade the engine guts, over Turbo.
I would hesitate to say it is better. Diesel has the torque.
The issue is building Diesel to last. $$$$$$$$$$$$$$$$$$$$$$$$ (That's 25K, unless you rebuild what you have.)

Can supply you with a Mark VI 7.4L Gasoline Engine core.
Standard machine work required, probably around $3500-$4500, not including the core and shipping for my engine.
Any Big Block GM is going to cost you $5K minimum, to build any core. It goes up very easily, very fast.

My short block has 96K and a known good ECM/pigtails, if you want to buy it.
No heads, they are spoken for already.
I can tell you where to source the pin out for the ECM, from a guy on GMT400.com.
I own his document and he has the copyrights, so you'll have to ask him to buy the paperwork to swap to the 7.4L.
You can also use the 0411 ECM with the 7.4L and your transmission. Same guy sells that pin out.

It can be programmed and flashed to any engine/modern transmission OEM configuration, unlike my black box ecm, which is pre-tuned for the 4L80E and may not work for your configuration.

Your tuner might ask you to go stand alone ECM/Trans controller, so he has extra parameters of adjustment. $$$$$$

Wouldn't take much to clean the 7.4L up at the machine.
The issue is you then need to build it stronger than OEM and mod your harness and my ECM or the 0411 ECM.

GM sent out the best 7.4L 99' gas engines right at the limit for the 5 year warranty.
The block is awesome, but the internals are carefully selected to fail on a timeline.
They require upgraded crankshaft and rods to run stronger than 5 years for towing.
It's not a bad option, just a bit of wiring work, that can get tricky and better than stock bottom end.
Worth every penny, if you got the dosh! Cheapest way out.

Finding fuel in remote areas is n longer a problem. You now burn gasoline.

Turbo the 6.2 Detroit is going to run $7500.00-$9500.00 with rebuild, inter-cooler mods and proper tuning.
Probably about the same as the 7.4L option, after everything is included, because of re-wiring. Depending on your skills.

Select a reputable turbo charger and the very best blow off valve and high performance fuel system pump / filter mods.
(Or do it cheap and screw it up).

There's a bunch of guys here who can tell you how to hack the build.
I'm not one of them. The $2000 price difference is the cost of a proper forged Diesel crankshaft, HD rods and heavy duty machine work for the 6.2L.
The price reflects QUALITY Diesel turbo charger components and most of the work performed by you, not a shop.
You could easily spend $15K for a shop to build tune and restore your 6.2L Turbo modified for the work you want, with transmission mods.
$20K would be cheaper than the Cummins and a great investment, if you choose parts wisely.

It would still be worth it. Your truck would be amazing. Very reliable. You would have a seasoned team to repair it.

The Forged Summit kit is entry level. (The cheaper non-forged kits would not even be on my radar).
https://www.summitracing.com/parts/cmb-03-0268/make/chevrolet

Dual stage, which would be excellent for your project, are worth the money.
If you can afford to install a Honeywell dual staged Turbo, do it.
It cost a bit more to tune and you will be very pleased with the performance.
You'll need the custom exhaust manifold to run it. It is still worth it!

Emissions, might be easier to meet with one over the other, so consult a professional Diesel tuner and your machinist first.
They might have the kit you'll want in the database from a previous machine shop build.

Your harness needs to be checked out and improved, but changing it could get messy on a Cummins Swap.

You'll need the extra cash you save, to rebuild your transmission to handle your new turbo 6.2L or 7.4L!

Don't forget your rear differential.
The turbo charger will bring out all the issues with the final drive line and brakes.

I priced the swap for a Dodge 2000 4wd 24 valve to a 12 valve, for eight months.
Researched everywhere.

Swapping to Cummins in your GM, is not really efficient use of your money, from my research.
You want a Cummins, go price a verified excellent Dodge 12 valve Diesel truck, and see what it costs, no mods necessary.

$$$$$$$$$$$$$$ Your talking $65K with crappy interior and bad wheels. And you will still own a Dodge Transmission!
Cough cough cough...

Hope this helps.

It's a great project!
Please post pictures of whatever you decide to build! :welcome:
 
Last edited:

nickknox

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I know I’m going to have to spend some money, but don’t want to spend that kind of money.

I can’t imagine hauling more than around 12k lbs. it’s just the wife and I and our loyal pup. So we won’t have a giant RV.

I just have no faith in the 6.2 hauling it, especially if we pull any kind of grade. I don’t want to be that guy backing up traffic at 42mph in the right lane
 

squaredeal91

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5.9 Cummins 12 valve
I've got a 6.2 with 6.5 turbo and it's fun! Really woke it up. Also have a 12 in my daily and there both good. Depends on what your expecting.
 

ByrdDog

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Look at the 1st gen VE-pump cummins engines placed in Dodge trucks from 90-03. The later P-Pump motors are crazy expensive, but I would think you can pick a 1st gen for a few thousand... Not sure on the cost to rebuild, but it wouldn't require anything fancy to meet your towing needs. Might check out Diesel Conversion Specialists - they make cummins swap kits for squares.
 

nickknox

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Look at the 1st gen VE-pump cummins engines placed in Dodge trucks from 90-03. The later P-Pump motors are crazy expensive, but I would think you can pick a 1st gen for a few thousand... Not sure on the cost to rebuild, but it wouldn't require anything fancy to meet your towing needs. Might check out Diesel Conversion Specialists - they make cummins swap kits for squares.


Will do, thank you!
 

peats

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72k5, 81c10 short step, 83k10 short fleet, 03 SSR. 25 chevy doodlebug
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k5 c10 k10 SSR doodlebug
Engine Size
406 360 6.2 5.3 171
The 6.2 doesn't respond as well to turbo as the 6.5 does. A 6.2 to 6.5 swap would be the easiest, cheapest power adder. The 6.2 still has value and could be sold off after a swap.
 

ByrdDog

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Chevy
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6.2
6.2's & especially 6.5's (good ones at least) are getting much tougher to find. You can buy an Optimizer 6.5 new still (I think), but it'll set you back about 10G's. I'd think that a rebuild & swap-in of a VE cummins wouldn't run much more than that...
Will do, thank you!
90-93 Dodge trucks; sorry for the typo.
 

peats

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k5 c10 k10 SSR doodlebug
Engine Size
406 360 6.2 5.3 171
6.2's & especially 6.5's (good ones at least) are getting much tougher to find. You can buy an Optimizer 6.5 new still (I think), but it'll set you back about 10G's. I'd think that a rebuild & swap-in of a VE cummins wouldn't run much more than that...

90-93 Dodge trucks; sorry for the typo.
The 6.2 to 6.5 swap would require little or no fabrication. That just simplifies the whole job. I don't know how much power the OP needs or his budget.
 

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