5.3L conversion in an '87 TBI?

Hi all, new here. I was directed here by a member over at Fullsizechevy. I was asking around over there about GM's most fuel efficient late model V-8 engine. I am looking to upgrade my 1987 Chevrolet Silverado to something a bit better on fuel mileage, as well as more reliable. At least, more reliable than my wore out 5.7L TBI motor.

The guys over at fullsizechevy recommended that I do a 5.3L swap, out of a low mileage '08 truck or something. Which suits me just fine, cause I am looking to do a junkyard build. I am hoping I can pick up an engine to do the swap in my 87 that will get better mileage than my 87 currently does, which is about 14 miles per gallon in general. So which engine would you guys recommend? Some people think that I should be able to get about 18 MPG out of the 5.3L motor. I'll certainly take that 4 MPG increase, especially these days.

Plus there might be a few tricks I could pull out, to bump it up another mile per gallon or two. Like long tube headders and a full exhaust system. Maybe an MSD ignition for hotter spark, and some low rolling resistance tires. Basically I am looking from something to be able to tow the boat to the lake, that won't break my wallet before I even get there. So which swap would you guys recommend? And what is your estimate on how much it would cost? Minus the cost of the engine itself, of course.

First off, a 5.3 sounds about perfect for your build. Even with my heavy 08 Z71, I can manage 20 MPG if I keep my foot out of it and drive 65... without the cruise on. Your mileage is all going to depend on the gears you have in it, how you drive it, and how it is tuned. I will say that my 5.3 only gets 13 mpg towing anything... be it 500 pounds or 5000 pounds. It has 3.73s.

A few tricks for the 5.3 for mileage? Higher gears, longtubes, and a good tune.

Cool so it seems that I am going with the 5.3L. Anyone here ever done the swap? I keep looking around for someone who has. Lots of people have told me that they have talked to people who did it.

5.3 is the way to go. Its the best mix between performance and cost. Plenty of people have already done the swap in your generation truck and lots more are in the process. I recommend looking for a gen III 5.3 (99-06) as opposed to gen IV (07+) just because they are more common and cheaper as well as parts are more common. If you find an 07+ for a good price then go for it. One recommendation I have and Im sure many people will back me up on this - buy a complete pullout rather than a a longblock and try to build it. Try and get all accessories, wiring harness, and computer with your engine. Believe it or not, it will save you in the end.
For mileage, I recommend and air intake, headers, and most importantly, a good tune. Gears have a lot to do with it too but if you go to high you will lose a lot of that pulling ability you need.
The cost of the swap will depend heavily on two things - how good a deal you get on your motor/trans, and how many mods you do. I spent roughly $3000 on my swap (mostly because of mods) but have seen it done for less than $1500.
And ya, your friend was right, this site is the best place to look for information on your swap.
These might spark your interest -
http://www.ls1truck.com/forums/lsx-t...tepside-6.html
http://www.ls1truck.com/forums/lsx-t...0-project.html
there are others just do some searching

eventhough im a new member to this site too this is the best site for your swap questions hence is why i became a member myself after being a visitor for the longest time.

Thanks for the helpful replies everyone. I was thinking, what about a mild cam to help out gas mileage? With TBI motors, putting in a mild cam can (under the right circumstances) net you up to 2 MPG. Now I am not talking about some race cam, or a monster. Just a cam that is slightly larger, and will work with the factory heads of a 5.3L.

im almost done swaping a LH6 5.3L in my 82 c10.just need exhaust and fan harness. it can get pricey, as said above make sure you get a complete engine with all acc and wiring. the motor i bought is from a 07 envoy denali it had a front sump oil pan so i had to get a truck pan and pick up tube. it will probally be easier and cheaper if you get a DBC setup and not the DBW. if you have any questions fell free to ask. i know i asked alot of questions during the swap.

read my build thread before you go with a Gen IV block!!! its hell man, ive had to modify so much crap to make it work an then find parts to make other parts work and blah blah!
99-06 imo swap to a DBC TB and have fun. get wiring harness/ACC tranny too if your old one is shot. save all the parts off your old stuff until you finish the swap. i had to hunt down stuff i didnt think i needed.
1700 for motor/trans no wiring/ACC
675 NP wiring harness
275 LTs plus 150 to powdercoat them
200 cam
125 LS7 lifters
45 LS7 lifter trays
25.00 LS2 wedge style tensioner
110 for ARP head bolts
70 for head gaskets
375 FAST TB
120 for TPS/IAT sensor
300 for AC bracket
70 PS pump/bracket
120 starter/ALT
50 for oil pressure, water temp sensors
110 for knock sensors
300 for Circle D 3200 stall
190 for Billet servos/Billet 4th gear servo
200 for upgraded FP/hot wire kit
500 for 05 radiator an e fans w NP efan harness
100 ecm
95 for coolant jug, cap
160 in AN fitting/corvette filter
70 for SS fuel line
300 for BNIB patriot extreme valve springs/7.4" pushrods

buy a complete pull out!!!! itll save the hassle!

Quote:

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Originally Posted by keniff

read my build thread before you go with a Gen IV block!!! its hell man, ive had to modify so much crap to make it work an then find parts to make other parts work and blah blah!
99-06 imo swap to a DBC TB and have fun. get wiring harness/ACC tranny too if your old one is shot. save all the parts off your old stuff until you finish the swap. i had to hunt down stuff i didnt think i needed.
1700 for motor/trans no wiring/ACC
675 NP wiring harness
275 LTs plus 150 to powdercoat them
200 cam
125 LS7 lifters
45 LS7 lifter trays
25.00 LS2 wedge style tensioner
110 for ARP head bolts
70 for head gaskets
375 FAST TB
120 for TPS/IAT sensor
300 for AC bracket
70 PS pump/bracket
120 starter/ALT
50 for oil pressure, water temp sensors
110 for knock sensors
300 for Circle D 3200 stall
190 for Billet servos/Billet 4th gear servo
200 for upgraded FP/hot wire kit
500 for 05 radiator an e fans w NP efan harness
100 ecm
95 for coolant jug, cap
160 in AN fitting/corvette filter
70 for SS fuel line
300 for BNIB patriot extreme valve springs/7.4" pushrods

buy a complete pull out!!!! itll save the hassle!

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dude.....thats over $6500 worth of parts......and you call this your "work truck"! lol!

the bad thing is i forgot parts

55 motor mounts
55 radiator hoses
275 for the 58x to 24x module

i got a lot of bolts/hoses/custom fittings from work (hydrolic hoses) to save from having to buy stuff.

i bought an LS2 cam first didnt want that anymore, bought a TB stall didnt want that anymore. i still need to rebuild the rear end (3:73s Tru-Trac) yep its my work truck. i got tired of the V6 and got carried away with the upgrades :)