I have a '62 with a clone 340 HP solid lifter engine. Built to 340 specs EXCEPT using composite head gaskets. Right heads, pistons, valves and later model rods too. The question is: would I get "seat of the pants" improvement switching from the Duntov cam to the LT1 cam ?
Looking for a little more low end grunt, don't care about top end results. I don't mind spending $250 +/- and an afternoon in the garage if there is enough of a gain.

Opinions or facts welcome. Bob C

 

I think you'd get a different "seat of the pants" feel. Don't think in drag race, you'd see much difference. Not for my time and money, anyway.

If you haven't already done it, you'll get more out of optimizing your ignition advance from stock than changing that cam.

 

Looks like so far, at least 40 people aren't interested in getting in the middle of this.

I am sure a real expert will be along soon to give you a really technical answer to your question. Not that it's really needed.

 

For low end grunt at the sacrifice of top end, just change the differential.

 

I will suggest considering the L79 hydraulic cam if you don’t care for high end RPM, it could make you happy till 6,000 if that is enough for you while offering more low end. Many say it is the best cam for a 327 period but you might miss the solid lifter sound.

 

Trying to find you an answer, found this table on line:
http://blog.garagistry.com/2012/02/c...cam-specs.html

Doesn't have the 340HP cam, so I'm not sure where it fits around the 365HP cam and the LT1 cam. That said, you're gonna need tall gears for either one of those with a small motor, and I can't see how you'd get more low end grunt with either of them than with the 340 HP cam.

 

Bingo!

And just because the Duntov cam starts pulling hard around 2800, doesn't mean it doesn't pull well at 12-1500. Mine does just fine if you mat the gas pedal at 1000 rpm in high gear with a 3.36 axle. If that's not enough for you, you have three lower gears to choose from. That's what they're there for.

The L 79 cam is a little better at low end but for the time/money, not worth the effort.

 

The LT-1 cam will make more top end power than the Duntov with about the same low end torque, so given your criteria, it's not worth the swap. As previously mentioned a more aggressive spark advance map will definitely yield more low end torque. The original '62 dual point distributor provided 24 centrifugal at a lazy 4600 and no vacuum advance.

My SWC's 327/340 has a single point distributor with the same centrifugal curve as above and a 15" VAC, but it didn't pass The Two-Inch Rule, which caused idle instability and stalling. After getting a blank look from the dealer service department and bad advice from so-called "experts" I figured it out myself circa 1965 and installed the 365/375 HP 8" VAC and weights and springs, which brought the 24 centrifugal all in at 2350. It didn't detonate, but the improvement in low end torque and fuel economy was noticeable and it would idle all day at 800-900 without having to blip the throttle every 30 seconds to keep it from stalling.

It's all explained in my tuning seminar... easy advanced search... threads stated by me. There aren't many.

Determine your current spark advance map, then get as close to the 365/375 HP map as you can. You'll need a B28 VAC (Airtex 4V1053 if any are left, about ten bucks), and your existing weights are probably okay. Just install the black springs from the Mr. Gasket 928 spring kit and go from there.

Duke

 

Thanks for posting that factory cam spec table! I replaced the cam in a 350 block that was in my ’62 way back in the mid-70s (walked into the dealership and asked for a good hydraulic 350 corvette cam). I was happy with the results, but honestly had no idea what I needed or ended up getting. I’m now starting on the drivetrain rebuild on that old C1 and I’m going to try to backtrack on what I actually have.

 

I might be wrong, memory not what it was, but on that chart I believe the 178? cam was the 1970 LT1 cam.

 

Here's a good overall comparison of the cammed engines you're looking at.

 

"Just?" That's allot more money and work.

 

I can change a rear end in a 62 in 45 minutes. Used to be a half hour, but I’m old niw 😂

 

I was thinking this same thing for my C2. Ride Tech makes a C2 setup with a 9 inch Ford 3rd member. Downside, it’s kinda pricey.

 

Eeeeeyeah, "Just" change the differential.

Nearly a year ago the OP wrote:
Swapping to a different differential ratio will do exactly as the OP wanted.

It's a heckuva lot quicker to swap out a differential than to change a cam.

 

Yea but they are heavy.

 

That's why they invented jacks for differentials and transmissions. Better it is to work smart than hard.