Anti-LS to doing an LS--beginning of a build thread.

76z28

Veteran Member
Jun 29, 2009
2,541
bakersfield
Well, the title says it all. I was never a HUGE fan of the LS since I have always loved my big blocks. I have a 68 Camaro that just doesn't make the power I want. I really wanted to do a big block, up until I realized how freaking tiny the engine bay is compared to a 2nd gen camaro. So, I decided I will just build the small block, but when looking at my goals, it wouldn't be "cheap" or very streetable. That's where the LS steps in.

I did a bunch of research for trying to turn a 327-383 small block 6000 to 7000 rpm while having a pretty tame idle and making over 400hp. Can a gen I small block do that? Absolutely... the issue comes in when you have to retro fit to a roller cam, buy a new crank/rods/pistons for any stoker set up, and heads to support all of that.

Browsing facebook market place I found an LM7 for 450 bucks, that has good pistons, rods, crank, and block. So I shot the guy an offer for 350 and he accepted it.

The plan:
Rebuild the shortblock using a ball hone, new rings and bearings. After pulling a few rod bearings, the think looks amazingly new, however, I would like to get new ones instead.
Use a summit pro LS stage 2 cam(or similar):
Duration at 050 inch Lift:
226 int./230 exh.
Advertised Intake Duration:
275
Advertised Exhaust Duration:
283
Advertised Duration:
275 int./283 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.600 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.575 in.
Valve Lift with Factory Rocker Arm Ratio:
0.600 int./0.575 exh.
Lobe Separation (degrees):
113

I will likely use the 302-2 oil pan, but not sure on mounts yet.
Try and find an LS6 or LS1 intake
Headers

Th350 2800 stall, 3.73 rear gears.
I would like to run mid 12s to high 11s with this set up, but who knows. Anything will be better than the current mid 14s it runs.
 

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VandykeT/A

Veteran Member
Feb 11, 2012
130
Hurley, VA
I would swap over to a 4.8 piston while it’s apart to bump compression. The 5.3 has a dish 4.8 is a flat top. And if you really wanted to go the extra mile you could bore to 3.898 and have a iron ls1 and over 11:1 compression with the 862/706 head that came on the 5.3. I’d feel better about the cam and converter choice in a 5.7. LS engines peak torque a lot later than a sbc. Just thought I’d throw that out there to try to help.
 

Jfwyatt1

Member
Aug 30, 2018
39
Burnsville nc
Speed engineering ls swap headers fit great on my 70. The 4th gen ls1 oil pans work good and might be able to find used. Go for ls6 intake don't waste time with the ls1 there's a guy on ls1tech that sells ls6 intakes for around $300 he ships from baharan in the middle east but is a great seller. Try and find some 243 or 799 heads as well.
 

76z28

Veteran Member
Jun 29, 2009
2,541
bakersfield
I would swap over to a 4.8 piston while it’s apart to bump compression. The 5.3 has a dish 4.8 is a flat top. And if you really wanted to go the extra mile you could bore to 3.898 and have a iron ls1 and over 11:1 compression with the 862/706 head that came on the 5.3. I’d feel better about the cam and converter choice in a 5.7. LS engines peak torque a lot later than a sbc. Just thought I’d throw that out there to try to help.
I have thought about doing the LS1 set up but it's hard to get rid of good pistons and a nice cross hatch
I'm also trying to do this on somewhat of a budget.

Speed engineering ls swap headers fit great on my 70. The 4th gen ls1 oil pans work good and might be able to find used. Go for ls6 intake don't waste time with the ls1 there's a guy on ls1tech that sells ls6 intakes for around $300 he ships from baharan in the middle east but is a great seller. Try and find some 243 or 799 heads as well.

I don't believe the LS1 pan will fit a first gen due to steering being between the pan and frame.

As for LS6, if I can find one for 300, I would definitely buy it.

I will likely stick with these heads due to cost.
 

76z28

Veteran Member
Jun 29, 2009
2,541
bakersfield
Speed engineering ls swap headers fit great on my 70. The 4th gen ls1 oil pans work good and might be able to find used. Go for ls6 intake don't waste time with the ls1 there's a guy on ls1tech that sells ls6 intakes for around $300 he ships from baharan in the middle east but is a great seller. Try and find some 243 or 799 heads as well.
Do you have a link to that ls6 intake? I can't find any ls6 intakes.
Might just use the truck looking at some of those prices.
 

76z28

Veteran Member
Jun 29, 2009
2,541
bakersfield
You're going to like the LS platform when you're done.
I'm getting ready to fire up my second one next weekend, 70 with a new GM LS3.
Good luck👍
I am a LONG way from where you are, but I hope you take a video and post it for us to watch!

I decided to throw some flat tops in it since I have it apart. They are cheap and I don't want to bore the engine since I don't need to.
 




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