LS2Monte

iTrader: (4)

Hey guys, well I've already done one LS series swap and Im itching to do another. The LQ4 in my monte runs awesome, and the car is pretty much built to be raced and have fun with. I'm looking to do another swap but build it for a cruiser and economy.

The car I'm looking at right now is a 64 4 door Chevelle. It sits bone stock right now. I"m thinking about picking up a 4.8 or 5.3, backed by a 4L60e, and a 2.73 or 3.08 rear gear.

I'm wondering what a stock, tuned, 5.3 and 4L60e combo could net in terms of mileage? From what I've seen, the car will probably weigh 3200-3400 lbs once finished.

Any input?

Thanks guys.

luckyhenriksen

iTrader: (1)

Sorry, no help, but I love the idea! Ive thought about it several times myself. Buy a a cool old 4 door car for cheap, throw in a small 283 (5.3 is wayyyyy better) and an overdrive, try to get get the best milage possible. Then add comfy seats, nice stereo, and go cruisin.

thunderstruck507

iTrader: (18)

Well I dunno about that, but I can get as high as 25mpg highway with my car now.

I would rethink the high gears though, I didn't see any mpg loss going 3.08 to 3.42, in town mileage actually went up because I wasn't lugging the poor motor as much on hills and such.

ls1nova71

iTrader: (4)

I would think low to mid 20's would be a very real possiblity, if you can keep your foot out of it.

NateLS1

iTrader: (4)

I wouldn't do a 4.8..blah. Im pretty sure the 5.3's and 4.8's get the same gas mileage anyways.

BTW, I would love to see your Monte.. where on the cape are you from? I live in Sandwich and work in Bourne.

Shawn MacAnanny

iTrader: (12)

I wouldnt go with anything less than a 3.42 or so as mentioned. You'll probably be running around 27" tall tires and moving 4,000lbs. That would most likely cause the engine to lug which wouldnt help with fuel effienciency. In my 94 camaro LT1 i have 3.73s car has 163k on it, weighs about 3600lbs, just bolts on and cruising at 75mph i see about 2700rpms and still get 23mpg. So rpm doesnt really kill fuel ecconomy, engine load does.

Why not use a 6.0L? It'll give you a little more low end torque for getting that car moving

Bo185

I was thinking of doing the same thing with a 56 4dr hardtop I pick-up few months back.

I was thinking a 5.3L 6l80 and 3.08's, with the nice first the gear the 3.08's will help the the hwy rpm's nicely. It should get 25 mpg easy.

The 4.8's are CHEAP though! With a 4l60 though you will need at least 3.55, but if its all hwy miles 3.08 might be better.

Just run whats in the car when you get it then swap to tall ones later.

LS2Monte

iTrader: (4)

I'd honestly need to get 25mpgs to justifty it as my daily driver. I figure a 4.8/5.3 can be picked up cheap enough. Then just get a 4L60e from a fbody or 2wd truck, or even a T56 if I can get one for a decent price. Car will be rebuilt to make it reliable, but body wise, I wanna leave it all stock and make it mechanically sound.

I actually live in Sandwich...the car is off the road for the winter and will be going back on come April.

V8Rumble

iTrader: (9)

Almost exactly what I was gonna say...

G-Body

iTrader: (4)

I would think that you could get 20`s. When I had my 5.3L in the el camino I was getting 13-15 in the city and I did get 22mpg on the highway once....towing a suburban, I think I got good mileage cause I kept my speed down doing that. I swapped to the 6.0l and got about the same. Then I leaned out the tune with a pseudo lean cruise.....got it up to 14-16 in the city and 18-20 on the highway. If I drove it easier I could probably get better, my usual highway speed is 75+ and in the city I beat on it like a rental. so with a 4.8/5.3 you should get better if you can keep your foot outta it.

LS2Monte

iTrader: (4)

I'm actually leaning more towards a T56 now. I've always wanted a stick car, and with a 5.3, T56, and some 3.23s or 3.42s, the car would be fun to drive and also cruise down the highway nicely.

luckyhenriksen

iTrader: (1)

That will be a really fun car. Keep us updated and post some pics =]

Kenova

iTrader: (4)

If you use a T56, I think you would be better off using 3.73s. Sixth gear would pull the revs way too low at any "economical" highway speed.
I have a 4.8 in my Silverado. It's no record breaker in the performance arena, but it does well for what I want. If I can keep my speed under 70 mph. I can nail down 25 miles per imperial gallon (US gallon is smaller).
If your ultimate goal is mileage, then I would suggest a 5.3 with Displacement On Demand and a 4L60E. Most of these engines are used in pickups with 3.42s and 30-32 inch tires. A lower gear would put less load on the engine when the DOD is activated, increasing the amount of time it would spend running on four cylinders.

Ken

ggk

iTrader: (1)

if you are going t56 then why dont you go 6.0 of 5.7.
ls1 fbodies are known to get 30+ highway heavier then your car will be so mind as well have the power on tap.

LS2Monte

iTrader: (4)

I'm more or less up for any LS series motor....per its in my budget. Not going hog wild with the build. 4.8s and 5.3s are cheap and pleniful. LS1s always cost more, as do the 6.0s.

DOD sounds like a possibility.

ryanvv355

iTrader: (17)

Not really any help to your question, but, going with the DD theme.

I am thinking after the Oldsmobile is done I am going to get a rolled over Denali at an insurance auction, LQ9/4L65E/AWD ~$2500-3000. Take the dash, column and seats out, remove the body and transplant a 67-72 GM truck body on the Denali frame. Put the Denali interior stuff in the old cab, have all the good stuff like Onstar, heated seats, Bose sound and cruise. That will be my daily driver.

luckyhenriksen

iTrader: (1)

That would be awesome! (I am a big 67-72 truck fan)
it would be even cooler to transplant a 67-72 suburban body on that chassis

slick00m

iTrader: (8)

I swapped an LQ9 and T56 into an 89 IROC and when I fist got it running I still had the 3.08 rear. I was able to get 30+ on the highway doing 80 + or -. The engine was completely stock at that time, even the stock truck manifold. Now I have 4.11 in the rear and it isn't quite that good any more but I still get over 25 on the highway.

subtlez28

iTrader: (15)

If you go T56 (and you should) I agree w the 3.73 idea. With a .50 overdrive it will be fine. My 02 Z28 gets 29MPG at 80 w the air on. Now, the Chevelle is a little heavier and not so aerodynamic. So the 3.73s should help w that.

W/ the T56 I don't see why you wouldn't see 25+ mpg. Especially if you keep speed down (otherwise the aero will kill MPG).

Good luck, keep us updated!!

digitalsolo

iTrader: (24)

My heads/cam 5.3 made >400 RWHP and got 29-30 mpg highway with 4.10s and a T56.

This is in a 2600 lbs RX7 with no p/s or a/c though. ~70-75 mph cruise speed.