Comp Cams XE268H vs. XE274H? Opinions?

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Stock all the way...cast iron...numbers...that sorta thing...The bore is .030, but comp ratio is 10:1...I realize that a stock cam is the safest bet, but I would like to take advantage of todays technology, keep the idle reasonable, and maybe gain a little performance...

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Negative on both...Sealed Power .030-over flat tops...heads untouched except for new seals and springs...The comp ratio is 10:1 .

The 268 was my first choice but the 274 is tempting...

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I appreciate your interest...I understand that compression ratio is a value that needs to be factored in when determining the application of a camshaft...Suffice it to say that the pistons are advertised as .030-over replacements for the 383 HP engine...I do not know what the EXACT compression ratio is, and I frankly don't care. I would assume that it is close to what was advertised...that's good enough for me. This is not a race engine. I just wanted to hear of fellow hobbyists experiences with the cams in the subject line. Thanks

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I appreciate your interest...I understand that compression ratio is a value that needs to be factored in when determining the application of a camshaft...Suffice it to say that the pistons are advertised as .030-over replacements for the 383 HP engine...I do not know what the EXACT compression ratio is, and I frankly don't care. I would assume that it is close to what was advertised...that's good enough for me. This is not a race engine. I just wanted to hear of fellow hobbyists experiences with the cams in the subject line. Thanks

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Ok, seeing you have a stock cam now, i would get the .268, it should wake it up nicely, the .274 would sound better, but with stock compression, you may not like it as much as the .268, now that thats said, you really should care about what you build, especially the compression when it comes to picking a cam, if you get defencesive about it, then knowone with any real knowhow will bother helping you, then your responces will be slim, & thats why your asking Qs, for help "right", so don't be quick to get mad, because doing the math on any build is knowledge, & ammunition for any future upgrades you may want to do. [/quot

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I appreciate your interest...I understand that compression ratio is a value that needs to be factored in when determining the application of a camshaft...Suffice it to say that the pistons are advertised as .030-over replacements for the 383 HP engine...I do not know what the EXACT compression ratio is, and I frankly don't care. I would assume that it is close to what was advertised...that's good enough for me. This is not a race engine. I just wanted to hear of fellow hobbyists experiences with the cams in the subject line. Thanks

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if you were at a true 10:1, I'd say go for the XE274, but you're not. you may be waaaay off of that. I'd go conservative and go with the XE268, otherwise the car might be pretty doggy until 3500 RPM or so.

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Finally someone brought up the bottom end. I too would go with the 268. Only because of maintaining a nice driveable bottom end. With Stock intake and exhaust, and no plans to mod, it very much sounds like a casual driver. I doubt you want to be hottrodding it all (or even most of the time). The powerband for the 268 should begin about 1800-2000 rpm. The 274 will be higher, probably about 300-400 higher. Having to slip the clutch at 2400 from every stop gets annoying in casual low-performance driving. Sidestepping the pedal while having fun is a different issue.
The 274 is a risky choice in your combo, and it would be held back by the intake/exhaust/compression

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I appreciate your interest...I understand that compression ratio is a value that needs to be factored in when determining the application of a camshaft...Suffice it to say that the pistons are advertised as .030-over replacements for the 383 HP engine...I do not know what the EXACT compression ratio is, and I frankly don't care. I would assume that it is close to what was advertised...that's good enough for me. This is not a race engine. I just wanted to hear of fellow hobbyists experiences with the cams in the subject line. Thanks

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The hp BB cams in 70 were 268 on the intake so do you want the same size or bigger?

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The hp BB cams in 70 were 268 on the intake so do you want the same size or bigger?

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The modern grinds ARE larger. Because of lift. The old-school stuff was high in duration for a given lift so diveability suffered in the true Hi-Po grinds. Now you can get good lift at reasonable duration. A lunati 60303 is .493/.513 at 268/274 (as I recall---if thats not totatlly accurate its close) Look at the lift of the stock 268 lobes, its not even .480.
Modern grinds rock.

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Your cam question really can't be answered properly without having some idea of your actual CR; that's why someone brought up the issue - they were trying to help you, not harass you.

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All I seek is personal experiences with the cams mentioned in the subject line with respect to a basically stock 383 HP. I have pretty much decided on the XE268. I was curious about the 274, that's why I posted...Sorry if I worded it improperly Thanks to all for info in that regard.

As far as a lecture in automotive math goes, after 33 years as a mechanic - I'm good.

It was never within the scope of this rebuild to delve into the exactness of measure...Were I to build a specialty engine, then that would surely come into play. This little 383 ran like a sewing machine, made great power, and was quiet...Its only problem was burning oil. Taper was excessive so I opted for the .030 over 10:1 flat tops from Sealed Power....That's it...All else measured fine...New bearings and gaskets, double roller chain, cam, lifters, springs and I'm done...Were it not for the oil burning issue, it would still be between the fenders!

Trust me, I do appreciate everyones input...I do not feel harassed, or defensive, or mad, or whatever...I've been doing this a LOT of years...You learn something new everyday...

Thanks

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The hp BB cams in 70 were 268 on the intake so do you want the same size or bigger?

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The modern grinds ARE larger. Because of lift. The old-school stuff was high in duration for a given lift so diveability suffered in the true Hi-Po grinds. Now you can get good lift at reasonable duration. A lunati 60303 is .493/.513 at 268/274 (as I recall---if thats not totatlly accurate its close) Look at the lift of the stock 268 lobes, its not even .480.
Modern grinds rock.

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I dont argue the design of the modern cams is better. However, that doesnt change how long the valve is off the seat.

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A modern grind 268 is not "the same size" as OEM 1970 268. And thats a wonderful thing!