July 19, 2011i was thinking about the possibility of doing a 5.7l to a 5.3l engine swap in my 96 chevy 1500. dont get me wrong i love the 5.7 but i want better gas mileage and more tune-ability than the vortec not to mention a fun project. i am just wondering if anyone has thought about it or heard about it or done it successfully. any insite would be apretiated, thanks
Forums : Engines-Gasoline : engine swap (2708 Views)
July 19, 2011Im sure it could be done. The easiest way would be a donor truck and swap it over piece by piece. Some fabrication would be needed but the electrical would be the biggest challenge. Another direction would be to put in a well built 383 (stroked 350) in a weekend, have allot less into it, and likely be happier with the results. The Gen 1 small block is a better low rpm torque motor where the 5.3`s are better HP motors at higher rpms. Depending on what you want to do with the truck, that may help make your decision.
July 19, 2011better mileage and 383 stroker do not mix.
What kind of mileage are you currently getting and what would you like to be getting? My 98 with 6inch lift on 37s will get 16.5 on the highway and 13ish in the city. I can`t complain about that but it is also not stock.
Another thing to think about is with a 5.3 swap (if you were to do it) once you get it swapped, a custom tune can be written to delete sensors. So getting it bolted into your truck may actually be the hardest part, not the wiring.
July 20, 2011Another thing to keep in mind, my dad gets 16-17 in his 07 avalanche. and that is mixed, i get just under 14 city in my 99 suburban and 17 highway. I know a guy that did a 4BT cummins swap on his 96 suburban, he was expecting low to mid 20s, and in my 93 6.5 turbo in a 3/4 ton i got 17 on a daily basis usually with 3000 pound in the bed. so if you want to push yourself up to that 16-17 MPG range, i would go with a 6.5. if you want to get up into the 20s, a 4BT might be better for you. i do know that for the 4BT you will need a 3 inch body lift to make room for everything, some fabrication for the mounts, and a tranny computer. He has the 4L80E. he did the entire conversion in his spare time over a weekend or two. and i believe he budgeted just under $4,000 for it. but he also mentioned that he was able to find most if not all the info he needed online, so there is probably a walk through somewhere online.
He uses his suburban to move his family around, not really to haul much around to my knowledge. so if you are looking purely for the best MPG you can get, the 4BT swap might be for you. seeing as there are no computers to worry about with the engine, you dont need to mess with that. and he said the install on the new tranny computer was straightforward. so figured i would throw out some more options for you to consider! if you were planning on hauling stuff, the 4BT might be for you, i dont know what their power rating are off hand. but i would lean towards the 6.5 as it is a direct swap over, it was an option for your truck so the whole swap should be relatively easy compared to a 5.3 swap or a 4BT swap. the 4BT (according to Wikipedia) produced around 130 hp and 355 foot pounds. so the 6.5 would have more horse, but less foot pounds. hope this helps!
July 20, 2011If you want opinions, I wouldn`t even consider the 6.5 But if you were to go to the good side (diesel) then a 4BT would be a superb canidate.
July 20, 2011Have to disagree with the 383 being bad on mileage. I read an article on a ht383 swap that ended up with better mileage after the tune, although I cant find the reference again so feel free to call BS. It does make sense though if you can make more torque at a given rpm, you wont have to use as much throttle to maintain. Your cam has everything to do with your power and economy. The HT383 cam is shared by the ramjet 350, the marine 350 and is focused on a high flat torque curve and less on horsepower. The ramjet uses 1.6 rockers and it shows on the dyno sheet by better HP and less torque.
All this doesn`t matter if you want a 5.3 just to have a 5.3 under the hood. It would be cool, no doubt. Im just giving a second option. I personally use my truck for pulling and like the earlier power range of the vortec 5.7. I didn`t buy the last year of a half ton with it by accident.
July 24, 2011most people experience a decrese in mpg with a 383 motor because of their right foot. Driving style always changes when there is "more power" below your right foot. I personally would rebuild the 5.7 that you currently have. With the frequency of the LS swaps into earlier model vehicles, its just like swaping any other motor. There are mounts, oil pans, headers, exhaust systems, and wiring harnesses already made for you for putting an LS into just about any vehicle. The stuff is definatley not cheap. I would say for half the money you could rebuild your 5.7 that you already own. Freshen the shortblock with new bearings and rings. Have the crank and rods checked. If you want some more performance you could deck the block and heads for a bump in compression. You could also get a different camshaft, something a little more aggressive but still good for a daily driver. The heads on the motor flow some good numbers so just rebuild the valvtrain with factory replacement parts. Possibly throw in a better ratio rocker if you want to. You could definatley see an increase in MPG with a fresh motor, add in a slightly more aggressive cam, some headers, and a tune and you could knock down some seriously good numbers that would any LS powered truck owner would envy. Just be smart how ya spend the money and do your homework on the parts so you dont buy them and they dissapoint you.
March 12, 2012I`m interested in how hard it would be to swap a diesel engine into a first gen. What made me come up with this idea is the power and gas mileage that comes with diesels, and the price for diesel is cheaper than gas. Not sure what type of diesel engine yet, just trying to see what y`all thought and if you know anything. Thanks
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March 13, 2012I built my 97 Z-71 with the 5.7L and I got 15 mpg in town and 19 - 20 mpg highway. I had 285/75/16 tires with 3.73 gears. I changed the cam out to a ZZ4 and changed valves to 2.02/1.6, used LT1 valve springs, changed out the injectors to the next larger size, Flowmaster exhaust, K&N filter, Helix TBI spacer, and I had the computer tuned. The tranny was also built up. It had the heaviest Borg Warner clutches available, Corvette servos, and a transgo shift kit. When it was stock it got 10 mpg town and 15 mpg highway. Better mielage can be obtained out of a 350. I had a Trailblazer with he 5.3L and 3.73 gears and it got 15 mpg and 19 mpg highway but it did not have near as much power or torque as my built 350.
March 13, 2012I don`t know where you can find diesel cheaper than gas it is generally about $0.40 higher a gallon. My father has parked two diesels. A Chevy 6.5L which the engine seized from an oil cooler line that came off while driving and he didn`t feel it was worth it to rebuild for the cost of diesel and a Ford 7.3L which he traded in for a new gas truck. I would like to have a Cummins but it is cost prohibitive for the swap or to trade and pay $45,000 for a new truck. I would want to buy new so I know that the truck has been maintained because a poorly maintained diesel cost much more to fix than a poorly maintained gas motor.
March 13, 2012Peak torque on a Vortec 5.7L is at 2800 RPM`s and the 4.8L, 5.3L, and 6.0L are all at 4,000 RPM`s. The ZZ4 cam pushed my peak torque to 3,200 RPM`s but I had so much torque throughout the whole range that it didn`t matter. If you want torque and mileage keep your 350 and build it. I pulled a 30 ft camper with both a stock 5.3L and my custom 5.7L and the 5.3L didn`t do near as well as the 5.7L. Mileage was about the same but ability to maintain speed in headwinds and hills the 5.7L did it where the 5.3L would struggle and lose speed. The 5.7L also had a disadvantage because of tire size to gear ratio. 285/75/16 to 3.73 where the 5.3L had 245/65/17 to 3.73.