I'm building a 67 RS autocross/track toy that can still be street driven. So far the car has a custom front clip with C5 corvette suspension and a C4 corvette IRS out back. Sitting in the car now is a small block and a NASCAR built super T10

My son blew his LS1 motor on Sat and scooped up a longblock locally, I now have a LS1 at my disposal (if it's rebuildable) Between he and I we have enough take off parts to pretty much make a complete motor minus the accesories.

So here's the question. Should I continue to keep the SBC that's in the car now or go with the LS1?

The SBC is a destroked 400. 4 bolt main, steel crank, wiesco pistions and chevy pink rods. Heads are 441's with 2.02 1.6 valves, fully ported and port matched to the headers and intake. Intake is an old school torquer single plane. Carb is a 650 mech. Estimated power around 425 or so.

LS1 would be a mild build with the usual bolt ons. Custom mega squirt efi controller, maybe put a carb intake on it and use the 650?

I would keep the Super T10 trans (4speed) that I have now in either case.

At this point on the car, I still have to do the fuel system and the wiring so either route logisitcally would be the same.

Anybody know the weight difference between a iron headed SBC and an LS1? What would you guys do if you had the choice?

I would go LS1 if it were mine. I think you would be saving a little over 100#.

Weight difference is ~80lbs for just the block.. heads are another 40-50 IIRC?

MegaSquirt is neat, but it's SO easy to make an LS engine run stand-alone with the factory EFI and coil-near-plug ignition that I don't know why you'd bother going aftermarket. (I run a 5.3 in my "Toyota" Rock buggy standalone)

Just my $.02..

Another vote for LS1. It will make more power and better MPG with just a cam and valvtrain upgrades. As I understand tuning is great with the factory ECM's but no first hand experience. THe factory heads flow more than a good set of aftermarkets for a Gen1.

Do you have just a spare long block or do you have the harness and ECM for the LS1?

I have everything from the throttle body to the oil pan including stock exhaust (from my header upgrade) I don't have any harness or electronics. I do have a good friend that is a megasquirt guru. I also don't have the fuel system components needed for high pressure efi. Mcloed makes a scattershield to mate my tranny, and the clutch components would be LS1. I've already installed the hydraulics at the pedal.

LS1 for sure. Now that the LS1 has been around for 14 years, I bet the cost to build an LS1 is similar to the old SBC. With similar cost, the LS1 with get better mileage, make more power, and be more street friendly. The factory ECU on these motors is so easily tunable that I would use it rather than the megasquirt.

Is there a good source for a stand alone LS 'how to'?

Mills I vote for the LS. Old school is cool but the LS in a 1st gen just looks awesome when done right. It is around 100# lighter than the SBC. You know you will get better power and economy out of it. If you want to look for anything for you out here in the sticks let me know. I hope to see you at the next Autox. Or if you need some extra hands one weekend let me know also

Yeah, I'm leaning more and more toward the LS1, just makes more sense. I wonder what the SBC is worth? I'm gonna need some cash to do it right. I also need to find an ECU for it. Rocky, anytime you want to come out to the beach and lend a hand, there's always something to do! Right now I'm helping my son put together they longblock and get it back in his car. He's in Poquoson, shorter ride for you.

Anytime let me know. Poquoson is right around the corner from work. Do you still have my number?

Yep, got it. You should check out hrfbody.org It's the local fbody club, lots of guys from the pennisula side. mostly into drag racing though.

I have totally forgotten about that site. I will check it out. I don't mind drag racers (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif)

It really pains me to say this....... but, I'd use the LS1. It's exponentially stronger(bottom end), the stock heads flow almost as good as my full-on race heads from a few years ago, and it's much more civil for street driving. Sell your SBC stuff and build the LS1, but I'd still use a carb....... something in the range of 830-850. The HP series 830 Holley would be my choice....... or go F.I., that is easy, but more expensive to turn up........

some of the best road racers started as drag racers who got bored going straight (IMG:http://www.frrax.com/rrforum/style_emoticons/default/gr_driving3.gif)

I am one of the bored ones.

When I finally get to redo my 67 Nova SS, it will be w/ an LS 1.

My camaro dynoed 375 at the wheels w/ bolt ons, cam, and tuning for torque. Mild porting would get it easily to 400, and mileage has dropped to 26 highway from 29.

in the Nova, which is 500 lbs lighter, w/ a converter, that would be damn close to 10's on the dragstrip, as the camaro ran 11.89 as a bolt on car.

If you do the LS1, please leave some links/tech for all who may follow...

Go to LS1Tech.com scroll down to the conversions and hybrids section.


Do some reading in the Dynamometer section on "EPS" cams also.


With the right cam, LS6 intake, all the bolt ons 450 hp is no problem.

Looks like I'm going to keep the small block for now. The long block we picked up for my son's car ended up being bad. Hole in the piston = bad. He's going to bite the bullit and save some more money to do his motor up right. So that means there's no extra motor for me, for now. I'll use the small block to shake down the chassis, and start my own LS build out of the car. It should bolt in fairly easily, I made provisions for it when I built my subframe. I know about the potential of the LS motors, I have one in my WS6 putting 340 to the wheels, only modded to ESP trim, could get more with an underdrive pully, I estimate his motor was well over 400 before he blew it up.

I would have voted for the SBC old school, dart has a great block that can turn 8K it you build it right.... Parts are cheap and easy to get, tried and true performance!

Looks like your already headed the lsx way. Thats my vote too. Im collecting thing now for it. I already picked a cheap 03 5.3. need a trans. as for ecms ebay has them stick with the 2000 & up. I'm told older ones have problems some times after tuneing. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/beerchug.gif)

Update with Photos!

New clutch is in!
(IMG:http://i539.photobucket.com/albums/ff356/n2sking/P1030520.jpg)

All race cars have to have a white drive shaft
(IMG:http://i539.photobucket.com/albums/ff356/n2sking/P1030515.jpg)

Brakes are now fully plumbed
(IMG:http://i539.photobucket.com/albums/ff356/n2sking/P1030546.jpg)

Fuel pump before
(IMG:http://i539.photobucket.com/albums/ff356/n2sking/P1030542.jpg)

And after cutting it down to fit my tank
(IMG:http://i539.photobucket.com/albums/ff356/n2sking/P1030543.jpg)

The LS1 Fairy also stopped by yesterday too!
(IMG:http://i539.photobucket.com/albums/ff356/n2sking/P1030551.jpg)

That's a tight fit, but clears! 315's on all four corners!
(IMG:http://i539.photobucket.com/albums/ff356/n2sking/P1030555.jpg)

This post has been edited by Beach Cruiser: May 29 2011, 01:43 PM