just got here

**bbadfred** · 03-04-2008, 09:36 AM

Hey all!! Just found this forum looking for good info on Ls series engines. I have a 67 gmc pickup almost done at the body shop and am trying to decide between a LT1 engine I have already or a ls1 style engine. I have a buddy with a 40 ford coupe with a 5.3 ls1 and a 68 camaro with a 400 hp 5.7 Ls1 and he loves them.

**bamaz28** · 03-04-2008, 09:51 AM

5.7 is the only LS1. the 5.3 is a truck engine something totally different i beleive. but why hunt up an ls1 if you already have a lt1? LS1 get expensive when modifying

**bbadfred** · 03-04-2008, 10:03 AM

Two words "gas mileage" and I dont have all the acesssories for the lt1. I am Looking for a complete pull out engine and trans with all accessories and ecm. I am not going for much modification on this project. With gas headed for 4 bucks a gallon I am looking for a performance/gas mileage setup.

**bamaz28** · 03-04-2008, 10:10 AM

LS1 isnt for gas mileage, my car is a m6 and if a baby it i can get at best 17 mpg. they are those that get over 20 but mine has been into some superchips treatment. and your putting it in a heavy truck makes it worse i'm sure. the LT1 and the LS1 are both 5.7 liters. you want gas mileage buy a honda!

**bbadfred** · 03-04-2008, 11:58 AM

My buddys 40 ford with 5.3 ls1 gets mid to high 20s on the road with a modified ecm and I have driven several vettes for dealer and have averaged 26-28 overall. we towed a car back with buddies 5.3 c15 and got 18.I also drove a 06 1/2 ton siverado cab and half for dealer and got 24 @70mph.Just drove a 08 impala for dealer 150 miles and got 27.8 overall @70 mph.These vehicles have instant and average mileage readouts on them.
Also aren't the 4.8,5.3 and 5.7 all LS1s?
I am going to use a 3.70 gear with 28 inch tall tires on my 1/2 ton truck with a 4L60 overdrive trans which should get me into the 20s mpg.

**bamaz28** · 03-04-2008, 12:03 PM

Originally Posted by bbadfred

My buddys 40 ford with 5.3 ls1 gets mid to high 20s on the road with a modified ecm and I have driven several vettes for dealer and have averaged 26-28 overall. we towed a car back with buddies 5.3 c15 and got 18.I also drove a 06 1/2 ton siverado cab and half for dealer and got 24 @70mph.Just drove a 08 impala for dealer 150 miles and got 27.8 overall @70 mph.These vehicles have instant and average mileage readouts on them.
Also aren't the 4.8,5.3 and 5.7 all LS1s?
I am going to use a 3.70 gear with 28 inch tall tires on my 1/2 ton truck with a 4L60 overdrive trans which should get me into the 20s mpg.

like i said mine had some superchip treatment, factory i would get 28mpg. mine has 2.73 gears
no sir 4.8 5.3 are not LS1's. 6.0 is LS2, the LS7 in the new c6 Z06's are 7.0??

**red99ws6** · 03-04-2008, 12:23 PM

4.8 5.3 and 6.0 truck motors are alot like and ls1. they are all generation III but as far as being an LS motor bamaz28 is correct

**bamaz28** · 03-04-2008, 12:35 PM

Originally Posted by red99ws6

4.8 5.3 and 6.0 truck motors are alot like and ls1. they are all generation III but as far as being an LS motor bamaz28 is correct

they are all iron blocks too right? i know the LS1 is all aluminuim.

**gnomee** · 03-04-2008, 05:30 PM

Welcome to the board!

If you have the LT1 it might be cost effective to just throw some money at it. With the right gearing and tuning it can be plenty fuel effiecient.

I'm an LS1 freak though I love the motor and would recommend it of the LT1 all day long. You could probably unload the LT1 and get ahold of an LS1 in the for sale section for a decent price.

**oobadoobin** · 03-04-2008, 07:17 PM

i am new here and can sympathize with you as i am starting an late model engine swap myself. I was looking for a 5.3 from a truck because they are cheap and are from the "ls" family of engines so there is a lot of aftermarket support. i would suggest if you are interested in genIII engines to go to the book store and get "how to build high-performance chevy LS1/LS6 V-8s" by will handzel. it will tell you the diffrence between 4.8-5.3-5.7-and 6.0. if you haven't checked w/ gm perf. parts lately they have a very large amount of gen III crate engines avail now. that being said, if you already own an lt1 ( assuming you have a gen II not one from the early 70's ) and your keeping it stock i would run it. I decided to shy away from an lt1 because aftermarket parts seemed to be expensive especially when you consider how much hp per dollar you get w/ the gen III engines. but I'm relatively new to all these new engines so I could be off in my opinion.