Which engine to get?

[gearys 5600]

Originally Posted by 67ChevyRedneck

Stay away from all 2007+ 5.3L engines. They have AFM and are having a lot of issues with oil consumption and the 4 AFM lifters going bad... I'd stick with the 06 and older 5.3L.

X-2 !!!! I just told a board member the same thing a few days ago..

[67ChevyRedneck]

I should have added that the "new" 4.8L from 07+ has almost as much power and torque as the 99-07 classic 5.3L but with no AFM, a "new" 4.8L from 07+ may be an affordable option as well, but I'm not sure, because nobody ever talks about them, everyone wants the 5.3L or 6.0L

I also don't mean to scare people away from new GM trucks. The tech I talked to said a lot of the problems are from people using the OLM to change the oil, which can be in excess of 7K+ miles. The lifters have a tiny oil orifice and can be easily plugged. He said on engines that get the oil changed with good synthetic from 3-5K miles there doesn't seem to be many issues, and you can turn off the AFM with a tune, but as far as these old trucks are concrened for engine swaps... just stay away from them.

[C10_ustacould]

When you have the tune redone, they will likely remove any "torque management" that robs power at the rear wheels. You will be very surprised with the power, I was! My 5.3l/4L60E has a ton of go!

[Average Joe]

Have you considered a SB swap? I realize the ls motors have better mileage potential and would definitely be worth it in the long run but the initial cost and downtime involved would be a factor for me. I would be curious about the cost of a good running 96-2000 vortec 350 from a junkyard. Throw a carbed intake on and your off and runnin' complete with serpentine accessory drive. The 4l60 as you may well know requires a electronic speedo or you can always drive by gps.

[jorgensensc]

Great info guys!! Y'all are really helping me out!

67chevyredneck, what is the "AFM" that your referring to?

Averagejoe, I thought about doing the sbc swap, but at the end of the day it seems that the ls would be a better swap. I'm not terribly concerned about the down time since I have another vehicle, but I don't want to take months either. I figure if I get everything ready before hand I should be able to knock it out in a couple of days.

I also thought that the cable x box would convert the signal, am I wrong?

Looks like I need to find a better deal on the 5.3 combo that what I've been quoted.

Thanks again guys!!
Posted via Mobile Device

[C-10 simplex]

Are you going to be doing any towing/hauling with the truck?

[67ChevyRedneck]

AFM is Active Fuel Management. 4 of the cylinders "shut down" under light load, essentially turning the V8 into a V4 motor to improve fuel economy. It is used on all 2007+ 5.3L motors. I think it was used before 2007, but not widespread, and I THINK only on the all alumnimum 5.3L, again, not sure on pre 2007 5.3L. OLM is Oil Life Monitor.

[jorgensensc]

Not towing too often. Mainly daily family duties.
Posted via Mobile Device

[luvbowties]

Originally Posted by jorgensensc

Great info guys!! Y'all are really helping me out!

67chevyredneck, what is the "AFM" that your referring to?

Averagejoe, I thought about doing the sbc swap, but at the end of the day it seems that the ls would be a better swap. I'm not terribly concerned about the down time since I have another vehicle, but I don't want to take months either. I figure if I get everything ready before hand I should be able to knock it out in a couple of days.

I also thought that the cable x box would convert the signal, am I wrong?

Looks like I need to find a better deal on the 5.3 combo that what I've been quoted.

Thanks again guys!!
Posted via Mobile Device

I'd suggest staying away from CableXBox--had bad experience(s) with them. So simple to add an electronic speedo--or even to remove the electronic sender & replace with mechanical sender to drive your cable speedo. If you still needed an electronic sender, you can buy one, made onto a short cable that splices into original cable to run it.
My 2-cents!...plus several thousand $'s worth of experience!!!

Re: 2nd bold quote above: In our area, the 5.3 gives such little trouble, the salvage yards are "backing up" with a supply of them. As such, you can buy one with miles(150K+/-) for approx. $550-750. I'll admit it's hard to find one with low mileage, but even then, it's waaaaay cheaper than $2500, including the 4L60E.
Another thing: Another poster mentioned the 4.8. It has just 10 less hp than the 5.3. One of the Hot Rod mags recently did an article where they bought one from junkyard, approx 178K miles(iirc), did not rebuild it, but experimented/dynoed with cams, carbs, and finally blowers. Said they were gonna keep increasing pressure and checking outputs UNTIL IT BLEW--just to see how much hp they could get. THEY ULTIMATELY GOT 1015 (MAYBE 1025) HP--BUT IT NEVER BLEW!!! Funny thing: they thought all along that they were working with a 5.3--they look so much alike. Only found it to be a 4.8 after they finished testing it and tore into it to see if they could find any abnormal internal wear!!! I'd not shy away, esp. if I was gonna heat it up a tad--on whatever I bought.
sam

[5150.4.67]

My$.02
Best mileage? 5.3. Nothing wrong with AFM, IMHO, if it's maintained. OD a must, 4l60.
I've had both (All early Gen III's rattled when cold due to harmless piston slap) and prefer the 6.0 for the 4 inch bore. Much easier to make loads of power with.... but this is not your goal.

Good luck.......

[birdistheword]

Well after looking through here I think I've decided to go with a 5.3 to replace my 454. Good thing is I already have a beefed up 700r4 in my truck.

[C10_ustacould]

Originally Posted by birdistheword

Well after looking through here I think I've decided to go with a 5.3 to replace my 454. Good thing is I already have a beefed up 700r4 in my truck.

I have a flywheel and adapter for the 5.3L/700R4 combo for sale if you need one.

[jorgensensc]

hey guys! Thanks for all of the comments so far. I've been a little busy with the holidays and such so I haven't really been on here much. So i found another 5.3/4l60e combo for sale. It comes from an '05 yukon with 33k miles. The tranny was rebuilt and has a 4l80 convertor (seller said that was recommended by the gm tech that rebuilt the tranny for him). It comes with everything but the pedal. The seller wants 2000. does that seem like a good deal?

Also, I thought I understood that the truck intakes have a return fuel line with regulator built in. If that is the case, my '72 already has a return line, so do I still need the corvette filter/regulator?

I am now understanding that the Trailblazer SS manifolds are a good replacement with no need to trim anything. .

Alan groves will provide the sanden ac bracket relocation so I can keep my vintage air.

I can move my th400 tranny crossmember and redrill it.

I think using the dirty dingo mounts would be best for positioning, but I think I need to use the 73+ frame stands. Will these mount easily to the bigger 3/4 ton frame?

Where can I get the power steering adapters to connect the 5.3 power steering box to my '72 gear box?

Also, whats the verdict on electric fans vs using the stock clutch fan? benefits?

Sorry for all of the questions. But I've been given the green light to do it,but will only be able to have the burb down for about a week. I need to have everything ready to go when I decide to pull the trigger.

Thanks for all of your help guys!!
Shawn

[brad_man_72]

No need for new power steering lines. Swap the fitting from the old pump into the new pump.
Posted via Mobile Device

[jorgensensc]

Awesome!! That's great info. Any more feedback on my other questions?
Posted via Mobile Device
Posted via Mobile Device

[Hart_Rod]

Originally Posted by jorgensensc

hey guys! Thanks for all of the comments so far. I've been a little busy with the holidays and such so I haven't really been on here much. So i found another 5.3/4l60e combo for sale. It comes from an '05 yukon with 33k miles. The tranny was rebuilt and has a 4l80 convertor (seller said that was recommended by the gm tech that rebuilt the tranny for him). It comes with everything but the pedal. The seller wants 2000. does that seem like a good deal?

Also, I thought I understood that the truck intakes have a return fuel line with regulator built in. If that is the case, my '72 already has a return line, so do I still need the corvette filter/regulator?

I am now understanding that the Trailblazer SS manifolds are a good replacement with no need to trim anything. .

Alan groves will provide the sanden ac bracket relocation so I can keep my vintage air.

I can move my th400 tranny crossmember and redrill it.

I think using the dirty dingo mounts would be best for positioning, but I think I need to use the 73+ frame stands. Will these mount easily to the bigger 3/4 ton frame?

Where can I get the power steering adapters to connect the 5.3 power steering box to my '72 gear box?

Also, whats the verdict on electric fans vs using the stock clutch fan? benefits?

Sorry for all of the questions. But I've been given the green light to do it,but will only be able to have the burb down for about a week. I need to have everything ready to go when I decide to pull the trigger.

Thanks for all of your help guys!!
Shawn

Definitely recommend electric fans (the computer will control when they come on). If you use ECE mounts, you won't have to move the a/c compressor. I would also suggest a ECE tranny mount bracket, provides more room for exhaust. NAPA should have the adapters. OBTW, the 3/4 T frame is dimensionally the same as the 1/2 T frames, they just have more bracing. Good luck with your swap!

[Vintage Windmills]

Originally Posted by gearys 5600

The 5.3 would be my choice.

All the 6.0's that I have had get horrible fuel mileage and rattle like a diesel.

I'm sure this will miff off the 6.0 fans on here, and I'm sure there is some 6.0 guru out there who gets 50 mpg. Out of a 500 h.p. 6.0

As the owner of an auto salvage for 23 years, I have sold lots of 5.3 and 6.0 engines. I am a huge fan of the 5.3 and not so much the 6.0
Posted via Mobile Device

Are you comparing apples to apples? Most 6.0's are in front of 4l80es and 4.10 gears and lugging another 1000lbs of truck around than the 5.3's. Put a 6.0 in a 5.3 application and see what the difference is. I had a 5.3 in a 4.10 truck and it sucked gas too.

[jorgensensc]

Originally Posted by Hart_Rod

Definitely recommend electric fans (the computer will control when they come on). If you use ECE mounts, you won't have to move the a/c compressor. I would also suggest a ECE tranny mount bracket, provides more room for exhaust. NAPA should have the adapters. OBTW, the 3/4 T frame is dimensionally the same as the 1/2 T frames, they just have more bracing. Good luck with your swap!

Thanks for the info hart_rod. I think I will still need the ac relocation brackets because of the sanden compressor, right? My understanding was that the newer compressors won't work with the vintage air ( got that from vintage air customer service). Was I misinformed?

I thought the frames were similar, but I was t sure if the 3/4 ton frame rails were taller or not. Thanks for the verification.
Posted via Mobile Device

[Average Joe]

Any updates on this?

[jorgensensc]

Not yet. I'm kind if paralyzed with indecision. I really want to do the duramax swap, but it will eat up most if not all of my monetary resources. That's IF nothing drastic occurs or goes wrong. I'm also waiting on my neighbor to letme know something on a 6.0 with 22k he had in his shop. Everything tells me the smart money is on a 5.3/6.0 swap, but the duramax would be just too darn cool and get better gas mileage. I just don't see how they differ much installation wise except for the initial engine cost/outlay. They both need motor stands (although the ls style motor ones are easier to come by commercially), they both need the wiring harness configured, they both need driveshaft mods, the duramax may be able to use the original radiator and intercooler, the duramax will need a hydrobooster, which wouldn't be a bad upgrade anyway). The ls swap will require a fuel pump which the duramax won't. The duramax will need the tranny tunnel raised though. But luckily mine unbolts so I should be able to add some height without too much drama. I just don't know.
Posted via Mobile Device

[Vintage Windmills]

The Dmax is heavy so you'd want to beef up your front end, factor that into the cost. And consider the trans you'd need behind it and how to control that trans.

[derrickmanx1]

Just got my 402 back from the engine builder and it made 496/479 with 16" of vacuum streetable 226/234 hyd roller cam. I think it will be fun to drive. I dynoed it with a crappy 870 street avenger carb that had trouble @4200 rpm with the secondaries and the top end a/f ratio was a little fat @11.8/1 It will be better with my fast injection.

[logansdad]

Originally Posted by jorgensensc

Not yet. I'm kind if paralyzed with indecision. I really want to do the duramax swap, but it will eat up most if not all of my monetary resources. That's IF nothing drastic occurs or goes wrong. I'm also waiting on my neighbor to letme know something on a 6.0 with 22k he had in his shop. Everything tells me the smart money is on a 5.3/6.0 swap, but the duramax would be just too darn cool and get better gas mileage. I just don't see how they differ much installation wise except for the initial engine cost/outlay. They both need motor stands (although the ls style motor ones are easier to come by commercially), they both need the wiring harness configured, they both need driveshaft mods, the duramax may be able to use the original radiator and intercooler, the duramax will need a hydrobooster, which wouldn't be a bad upgrade anyway). The ls swap will require a fuel pump which the duramax won't. The duramax will need the tranny tunnel raised though. But luckily mine unbolts so I should be able to add some height without too much drama. I just don't know.
Posted via Mobile Device

I'm in the same boat you are in with the motor choice for my 72 suburban. I keep going back and forth, because I too need to get the best gas milage. If you are considering the DMAX don't forget about the price of everthing goes up when you buy a diesel engine not just the fuel. The oil change is twice as much and price some normal replacement parts. From the research I've been doing the 5.3 w/od is the best choice by far. I wanted a 6.0 lq9 but after some quick math I can buy a low milage 5.3 and trans with the gear vendor for what most yards want for that motor about $4-5k I would expect with the 5.3 fourspeed and gear vendor you should see 22-23mpg

[jorgensensc]

Originally Posted by jorgensensc

Awesome!! That's great info. Any more feedback on my other questions?
Posted via Mobile Device
Posted via Mobile Device

Originally Posted by Vintage Windmills

The Dmax is heavy so you'd want to beef up your front end, factor that into the cost. And consider the trans you'd need behind it and how to control that trans.

I was planning on using the Allison tranny it comes with. The big bling springs on the burb should handle the weight of the duramax from what I have read. We will have to see I guess.
Posted via Mobile Device

[jorgensensc]

Originally Posted by logansdad

I'm in the same boat you are in with the motor choice for my 72 suburban. I keep going back and forth, because I too need to get the best gas milage. If you are considering the DMAX don't forget about the price of everthing goes up when you buy a diesel engine not just the fuel. The oil change is twice as much and price some normal replacement parts. From the research I've been doing the 5.3 w/od is the best choice by far. I wanted a 6.0 lq9 but after some quick math I can buy a low milage 5.3 and trans with the gear vendor for what most yards want for that motor about $4-5k I would expect with the 5.3 fourspeed and gear vendor you should see 22-23mpg

Your research and mine are both on the same track. My understanding is that the maintenance costs about even out due to the longer interval with diesels. Am I mistaken? I am being stopped by mere stupidity I'm sure. My big hang up is that the truck is originally a 402 BB, so if I put anything else in I'm not being "true" to the truck. Whereas the dmax is a 402 also. So I would still be true to the truck so to speak. Stupid I know.
Posted via Mobile Device