I am in the process of swapping a LQ9 in my 78 I have a cable throttle body because of adapting my old 2004R TV cable. I am also using the Holley HP control system for the wiring harness. It will plug into all the connections of the LS and is self learning unlike using a stock ECU and having to remap. if you need or want to change. http://www.holley.com/550-602.asp
I was going to buy a C5 but, so far I have been enjoying the swap process of figuring how to make things fit and work. Should get in the mid 20's MPG,

 

Thats an interesting engine, I think it was originally meant for cadillacs, why not go with the newer G4 ones with variable valves and displacement on demand, I think the LQ9 is an iron block while the G4 are aluminum so a drop in weight would be beneficial as well....

Anyhow, post some pics and give us a story about how you came up with this swap!


PS. my dream would be the L92 from Sierra Yukon tahoe silverado (6.2l)

 

 

The LQ9 is a really great engine. 400 hp with just an exhaust and tune and about 1/3 the price of an aluminum block 6.0. It also fits nicely in a C3

 

Thanks for Info, how is the market looking parts wise, I mean its a truck engine so what would have to be replaced to change its characteristics? (and make it fit)

 

Nice thing is almost all LSx truck and car parts are interchangable. I used an 02 vette batwing pan ($100) for ground clearance and an LS1 intake ($35) for hood clearance. When I did mine there wasn't much available for aftermarket accessory brackets, so I made my own. Now there are a half dozen to chose from.
Adapter plates were $100 when I did mine, now they're under $40 on ebay. You can even get a basic reprogram for $75 now. All the wiring instructions, pinouts, etc are online so you can do it yourself. An LSx swap is almost getting easy and cheap.

 

72lbs difference between LQ9 and LS1 I guess Since I'm around 80lbs overweight that should compensate nicely for my gut!

 

The steel blocks are abundant and the parts are interchangeable. I swapped the truck intake for a LS6, using my 2004R transmission since the bell housing mounts up direct using a short adapter bushing. My cross member should remain in the same place. Using C5 exhaust manifolds since no exhaust companies has stepped up to make a set for this swap.

 

are you changing heads? do they flow OK? Heck since there are some many interchangeable parts and these LQ9's are piling up on junkyards someone should put some BOK together for this engine build, economical use of junkyard parts to put together a +400hp LQ9

(BOK - book of knowledge)

Sorry for one of my day-dreaming posts, I would like my c3 to be faster than a 4 gen Fbody...

 

The 317 heads on the LQ9 are fine for 400hp, and that's with just the stock cam. Nice thing with the 6.0 is that you can swap the GM L92 heads (same as on LS3 motors). They easily flow enough to support well over 500hp.
I was planning on the cam/head swap on the LQ9 in my 68, but after driving it, I decided I really didn't need the extra hp with the stock size wheels and tires.

 

...horsepower is like sex-
you`ll always want more

 

I am using the 317 heads but doing a valve job. I am changing the cam to a 228/232 525 lift. This engine should be strong and pull hard which is what I have wanted. Looks stock from the outside until you floor it then hold on.

 

You guys always mess my plans up! first I wanted a 383, than a 496 and now the 6.0...
what would be the rev limit? will it pull nicely from idle?


what kind of trans options go with this engine? I guess since its computer controlled might as well pick up a comp controlled trans... or?

 

That's exactly what happened to me. My SBC engine was using 2 quarts of oil every 150 miles. Pulled the heads and a couple were missing the valve guides. The specs on my engine were unknown as I was 3rd owner and rescued the vette from Bubba's trailer court. Started looking for options. Overhaul what I had, crate, stroker? All over this board was told a cheap SBC wouldn't hold together and wouldn't make good power unless you spend $6-7K. I already had purchased the Holley EFI for my SBC so was going to EFI anyway. Stumbled upon the LS1tech forum and wow, opened my eyes to another world. Searched the forum for vette conversions and found several swaps. For about the same money would have a very nice modern engine with loads of power and unlimited options down the road. Turbo, superchargers and the bottom end is ready for either of these options.
As for tranny I optioned to stay with the current 2004R that I had bought a year ago. I like the gear ratios for my 3.08 rear end. Got the super heavy duty model from Monster and saw no reason not to use, it will bolt up to my LS with a different flex plat and a spacer bushing. Its controlled with a TV cable which I will hook up to the throttle body. You could hook up a 4l60e or 4l80e and have them computer controlled.
Now that I have one, I see LS engine and trans combo's with complete wiring harnesses for $3-4 just search ebay or craigslist.
Anyone thinking about this should go to LS1tech and search the conversions and newby sections. I spent many hours and found lots of answers. Gary 68 has been a big help for me as he has been down this road a couple of times.

 

Typical thought is that big cams kill low end hp. Not true with the LS motors. The combination of cam, heads, compression, and sequential fuel injection makes great low end torque. GM publishes torque curves on their crate motors.
As for trans, an OD is a big plus for milage. If you get under 2000rpm highway cruise, these motors sip fuel. If you're buying used, always best to get an engine/trans/harness combo.
Although one of mine is a richmond 6 speed, the other is a T10 4 speed.