how hard is it to replace this anchor with a 454?

clutchdust · July 24, 2002

i'm really thinking hard about just taking this P.O.S. 6.5 diesel (anyone ever notice the first syllable of diesel is 'die'?) and replacing it with a 454 gas. my biggest concerns are bolting a 454 up to a 4l80e and controlling the T/C lock-up. any thoughts on this? yes, i'm really that frustrated with this thing.

July 24, 2002

Physical swap would be a piece of cake. Everything should bolt right in. Electronics are another story altogether.

If you could find a complete wrecked donor truck, it wouldn't be too bad, I don't think. It would be a heck of a lot of work for you, but it's doable.

I think you might be better off trading or selling it, though unless you really, really love everything about the truck except the motor.

Tucson_02Silverado · July 24, 2002

echo the doable, but a lot of effort. For the tranny, there's throttle valve sensor boxes to control the 4L80E for those without a 96+ computer and harness.

If you don't want the third party tranny controller, then 96+ parts otherwise anything you like.

The donor parts need to be a 96+ computer and harness, 96+ 7.4L TBI, 96+ 7.4L Vortec heads, flush tank and lines, replace fuel pump for a TBI unit, 7.4L engine mounts, exhaust to exhaust manifold or headers if your inclined, if you do a crate engine you need all the accessory brackets, and accessories (AC, PS, ALT, etc) and the biggy if you live in an emission testing area all the other 7.4L emission stuff, if your in California, I not sure there is a engine swap exemption.

You didn't say if you need the high torque all time or if it was 3/4 or 1 ton.

3/4 and 454 used and in nice shape are hard to find (at least in Arizona) 3/4 and 350 seem to be most prevelant but all high miles, still good canidate for GMPP HT383 (425FTLbs) and beef up rebuild the 4L60.

But you have to decide on your finances. The HT383 is $3900+ and a 4L60 performance rebuild is around $1000 and you haven't installed it yet. $5000 makes an awfully good down payment on an 2500HD Duramax/Allison, but the payments........ No monthly payments but large outlay and effort or 6-7 years of payments.

I know, I know. I just finished going through the same type of decision last month. Although I have to say it was for a daily driver at $25K and not a hauler at $35+K.

A thought just occurred to me...with Arizona a "snowbird" state, I see a lot of snowbird's doing oneupmanship on each other. First they start with the 28' fifth wheel with dually 1 ton diesel, then move to a 32' fifth wheel, the truck barely makes it and besides their winter friends just got a 40' with a Class 4 rig. But after a couple of years the Class 4 and sometimes a Class 8 rig is too much for them and they just buy a condo somewhere and give up. Sooooo, if the logic holds, there should be a lot of Class 4 (TopKicks/Kodiaks) that are only 2 or 3 years old decked out in chrome accessories that have either Texas plates on the trailer and/or the rig or Michigan Plates on the rig and Texas plates on the trailer. I don't want to stereo type but the common siting is Michigan Plates. A 1998 or 99 repeat show winner class-4 4door Topkick with a Cat, diamond plate flat bed with removable dually bed went for around $29K on eBay a couple of months ago.

Sorry for the ramble....

clutchdust · July 24, 2002

actually, my plan is to find an older 454 that i can re-ring and go. can't smoke anymore than a diesel anyway. just going to put a q-jet and vacuum distributor on it and chuck all the computer crap and 6.5 anchor in lake mead. would it hurt anything to run the tranny without the computer control? wouldn't that be just like an old TH400?

i can't afford a new engine, crate or otherwise so even more so, i can't afford another truck. trust me, i'm not happy about that at all. i'd rather get a different truck but can't afford to make payments plus the bank owns my truck right now as part of my loan agreement.

Tucson_02Silverado · July 24, 2002

4L80E has all of it's shift point controlled by computer, you need the third party controller.

http://www.tciauto.com/electronics/

http://www.autotransinc.com/eplace.htm

So the only things you need is the engine mounts for the 7.4L and all the accessory brackets and matching accessories. Radiator fan shroud might be different. And of course flush the tank and lines.

Colorado Kid · July 24, 2002

I know you're frustrated right now, but I really believe the 6.5 can be made reliable for a lot less money and effort than you're planning to spend. A membership ($16, I think) at www.thedieselpage.com will get you access to their member forums and troubleshooting guide, and make life with a 6.5 much easier to take.

Good luck whichever way you decide to go.

clutchdust · July 25, 2002

hey kid, no offense but i noticed in your signature you don't actually own one of these boat anchors. actually, i would likely agree with you were it not for all the computer (mis)management. if it just had a standard injection pump with a real throttle cable and everything, it would be much simpler to work on and troubleshoot. as it is, there are modules to control modules and it's just an all around terrible system. not to mention the amount of technical support available from the dealerships and private shops is as bad as owning a bentley in zimbabwae.

Colorado Kid · July 25, 2002

You're right, I don't own one, but I driven more than a few miles behind them and I know a few folks who do own them. I also know one guy who swapped a 6.2 out and an Olds 455 in...He was never able to make it work very well, and he lived in a emission testing area and was never able to pass the e-test, so he did a bunch of work to make a slow stinky truck into a potentailly fast truck with vapor lock, overheating and transmission problems that was illegal to drive, couldn't be licensed and was eventually left in a field to rust out.

Nobody's mentioned yet that the gas and diesel versions of the 4L80-E use different torque converters (lower stall speed for the diesels).

You haven't said what year yours is, but I'm assuming it can't be a '93 because of you general complaint. There are a few spasms that the electronic pump versions can go through, but they really aren't that complicated, and the guys at the page I mentioed seem to have them pretty well figured out, eliminating the need for much expertise on the part of your dealer. (By the way, if you've got less than 120,000 miles your fuel injection pump is still under warranty, GM extended it). I'm not trying to be a smart-butt, and I know you're 6.5 has given you some headaches, but I seriously expect that you'll be setting yourself up for worse trouble if you try to swap in a tired 454.

All your accessories will have the wrong pulleys.

You'll have to create the fuel system all the way back to the tank.

Exhaust will all have to be fabricated

You'll need a trans controller, I'm not sure how a 4L80-E would act with no controller, but you might not even be able to get it in gear.

As mentioned above you'll need a different Torque Converter

If you descide to use the trans that came with the 454 you'll have to be creative to have a working speedometer, because the one in the truck is electric.

Probably 20 more details that none of us have thought of, because we haven't tried it.

I haven't taken offense, and you don't have to take my advice, but you did ask for our thoughts.

clutchdust · July 26, 2002

kid, all valid points. i'm glad you didn't take offense, i do have a tendancy to rub people the wrong way, especially when i'm frustrated (just the glory of me being me). after i speak to the other diesel guy i mentioned before, if he has no solution, i will probably do like you suggest with the other website. there were several good points you brought up i didn't think about like the T/C and accessories. as for smog, they don't do any smog testing on diesels around here so mine is registered as a diesel with DMV, i would just never tell them otherwise. if it were virtually a drop and swap deal, i would still seriously entertain the idea of a 454. with the amount of work involved that keeps coming up, it doesn't look nearly as do-able. if i can't get this P.O.S. figured out,i will likely sell this thing or forget to put it out the NEXT time it accidentally catches on fire.

what is sad is when i don't have problems with it, i kind of (and i mean 'kind of') like this thing. with a regular bed and an intercooler, it would tow my vette through the mountains at 65 without breaking a sweat.