Thread: Old Chevy big blocks vs. the newer LS1 and LS2 motors???

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I have had a 402 Chevy big block in my late 69 Camaro.Although i have owned the car for a long time i was wondering with my 4:11 gears,595 lift cam,28 inch tall tires maybe it is just not a great street car.I don't know about the gas mileage because I have never taken it far and has been in storage for a while.I was guessing my engine puts out between 425-450 Horse power.It is a durable motor.Forged pistons,crank,and rods.As much as I like it I want to enjoy it and I don't think it is a very streetable car that I can take very far without stopping for gas.I also use a 150 shot of nitrous and the motor can take ebery bit of it.I guess Im getting a little jealous of some of the LS1 engines making great power(getting descent gas mileage) even if it is not a big block.I know it would cost alot of money to swap an LS1 or LS2 in my car but maybe i would be driving it more and enjoying it.Has anyone done a swap like this or should i keep my current setup???

Keep the current. the Ls1 isnt going to make any more power than you have now wthout spending a lot of cash. and LS1 parts seem to be Really expensive. Remember "There is no replacement for cubic inches"

My car runs good on pump gas too.Only thing is that big lopey idle and the 2 chamber flowmaster mufflers(loud).Other then that I wish i had an overdrive trans for the 4:11 gears.i will probably keep my current set up because I don't even have a good set of aluminum heads yet to benefit all my other high speed parts.The use of NOS is a perfect match with my cars set up.I only use it in 3rd and 4th gear and when i hit the button it is the closest thing to a rocket ship while still getting traction and i also use it on pump gas 94 octane and never have had any problems with nitrous.About 8 or 9 years ago I did break it when I got stupid and over revved it and I lost my rod bearings but all the parts,pistons,crank,rods were in good shape for the rebuild.It looks like I will be staying with old Chevy Rat Power for a while!!

Dont do it man, i work on the new f-bodies....yes it is true that you can get gobs of Horse out of these LS motors with what seems to be "easy" mods. But just to name a few things here:
An LS1 Hot Cam is the cam of choice.....the cam alone is around $400

The LS1 have extremely weak and cheap oil pumps....i guess GM figured they could save a few bucks there. Around 60K miles they fail for no reason.

Do you really want a computer on your car?....think about the head aches you get from your desktop at home....now multiply that by 100 and shove it under your hood.

For the money you are ganna spend on that LS1 or LS6, or the new Ls2 you could have a pretty stout 383 that will get you around 12-19 mpg....i get 10mpg in my stroked BBC, most people get sick when they here that, but i am more than happy with that. She has done the Hot Rod Pwer train 2 years in a row and only went through a water pump.

There is a kit made to swap an LT1 or LS1 into a first gen, and it seems pretty murphy proof, but i wouldnt spend the money for the motor....just not worth it for what you get out of teh box.....now if you score one from a totalled Camaro or Fireturd make sure you strip out the wiring harness

Im not really worrying to much about gas mileage anymore.I have come to my senses and I do not want to spend Thousands of dollars on a motor in which the car I drive is not my every day car.The one thing I can use in the future is a great set of aluminum oval port heads that will make at least 50 more HP.I have no idea what my gas mileage would be with my 402 Big Block because my gas gauge doesn't work.One thing is that distinct sound of the Chevy Rat Motor Big Block can't be duplicated with a LS1 or 2 motor.With 4:11 gears 28 inch tall tire,big 595 solid lift cam, I would say between 8 to 12 miles per gallon???12-19 miles per gallon for a big block is hard to believe or do you have a small block?? What size engine do you have and what are your rear end gears??

yeah i am running a 454....with 3.73's outback and a Muncie 4 speed

Originally posted by 4speedTerror
yeah i am running a 454....with 3.73's outback and a Muncie 4 speed

3:73's are much better then the 4:11's I have as far as getting better gas mileage.I don't think with my cam that 3:73's would work well with it, plus the 4:11's seem to be the right gear for the engine combo.I have a Muncie M-20 also that I believe sometimes when I have it in 4th gear pops out and goes into neutral but its not a big problem yet.I would never have a automatic in my car.My 396 bored .30 over is all forged pistons,rods,and crankshaft.It works great with my 150HP shot of nitrous when tuned properly.Iwish i had maybe a 427 or a 454 at times but i was thinking about buying the newer Holley Ovalport aluminum Heads which drop compression while increasing torque and power above 4000 rpm's by about 50 each.That could save some weight and make up for the 52 cubic inches the 454 has on me.I really don't race the car I just want the car to be my ultimate cruising car.The car has been sitting for many years in a garage because its going to cost me some money to get inspected,it also needs some floorboards, but hopefully soon I will be able to drive it around town and show off

You could use the money you would spend on the motor swap to buy a Doug Nash 5 speed. They generally have a 1-1 high gear, but much lower 1st and 2nd, so you can swap to a 3.08 or 3.23 rear gear and then 5th would be like an overdrive for you and you would still have that neck snapper in 1st and second. And since you said your M-20 has a problem that would solve it too.

Pat

I have had a chronic problem with my Muncie popping out of gear, if you ever have the tranny out of the car put everything in neutral....there is a whole in the case that you should be able to see all the gears in line. There should be hole about as big around as a pencil lead that lines up all the way through. and if it doesnt align then you should be able to see the problem gear.....i have always had my tranny guy adjust it because i am still a little scared of that area.....or you could have bad shift forks like i did...and continue to have.....i tend to be abusive when i am running her....lol.
I totally hear you about the 4:11's....i was running 4:56's and the way the motor would wind up was a total rush....as soon as i dumbed down to the 3.73's i lost almost a full second off my times....my 60' times were horrible.....but i can cruise on the highway 70mph at 3200 on the tac. better than the 4300 i was at....lol

I have not heard of many Chevy's with a Doug Nash 5 speed.If 4th gear is a 1.1 ratio I wonder what fifth gear would be??Is it easy to install a Doug Nash 5 speed in a Big Block 69 Camaro??Also how much are the transmissions??As far as lowering my gears in the back I would have to have someone calculate what my final drive ratio is.

I know Richmond makes a whole kit for a 5 speed....new drive shaft, cross member, all the things you would need for the rear end.....all you have to do is drill the new holes in the frame for the new cross member. really cool kit

I actually had my Muncie M-20 out and a transmission expert told me that the transmission needed a rebuild.I think the M-21 is a better transmission although im not sure what the differences are between the two.He gave me a riduculous price like 860$ to rebuild my M-20.Like I am some moron or something.I can get a rebuilt tranny M-21 for about 500$.With the 3:73's at 70mph you get 3200 rpm's??How tall are your tires in the back??Actually with the 4:11's its not that bad but I have no speedometer hooked up so I really can't say at 70mph with a 28 inch tall tire what RPM's I would be getting.Also I have never been on a highway before with my car.

Yeah I have seen the Richmond's in the Summit catalog.Quite pricey.It might be something in the future when I have some money I might think about, but matching gears with the Muncie to the Richmond is that the same as calculating a Doug Nash 5 Speed??

The Doug Nash I was referring to does not have an overdrive. 5th (High) Gear is 1:1. But the first and second gear are lower than your Muncie so you could run a higher rear-end gear , like a 3.08 and still have good acceleration in the lower gears like you have now, but 5th gear would drop your RPM considerably.

I have no idea what one costs new, but they have been arround for a while and if you are patient you could probably find one used or at a swap meet. They should bolt up to your bellhousing or scattershield. You will have to fabricate or move your crossmember and come up with a shifter if one doesn't come with the tranny.

It's worth a thought.

Pat

The Doug Nash Trans is an interesting thought.I have also heard of the T-56 6 speed from the Viper.I have heard of some camaro guys swappin it in there 69 camaro.