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Old 06-03-2012, 09:34 PM   #1
shipma2
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low comp 454 block or high comp 396?

which is better? the high comp 396 block or a low comp 454? im thinking for the 2wd speed truck a 396 would be better opinions or other ideas please?
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Old 06-03-2012, 09:49 PM   #2
Firebirdjones
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Re: low comp 454 block or high comp 396?

No substitute for cubes. No one really builds the little engines anymore unless it's a numbers matching deal. Even 454's are small by todays standards.

I really don't know what your plans are, but that's going to be a deciding factor. Being a big heavy truck shaped like a brick, I'd opt for the larger engine

With todays crap pump gas low compression isn't necessarily a bad thing. The amount of compression you can get away with depends on alot of things.

Are you worried about performance? Want to run pump gas?

My old 79 454 1 ton pickup (original long block never opened) was rated at 8.5:1 but in all actuality it was probably more like 8:1. I installed a little edelbrock performer camshaft, performer intake, and a set of 1 3/4 inch headers with a 3" exhaust, and that 5,500 lbs. truck would run 14.70's in the heat I mainly did those mods for more towing power as that's what I really used it for. Nice thing about it, even with an aggressive tune, I could load 10,000 lbs. behind it and tow without worry of pinging on 91 octane.
Eventually spun a bearing so I swapped in a GM crate HT502, another low compression engine (9:1) but another 48 cubes and a roller cam, absolutely love it. My situation (towing a 28 foot trailer) wouldn't allow me to even think about a 396 in there. It would get the job done, but it's just not enough butt to satisfy me
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Old 06-03-2012, 09:51 PM   #3
shipma2
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Re: low comp 454 block or high comp 396?

hmm u may be right by putting a bigger cam in a 454, it would highten power and comp. i may look into that .
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Old 06-03-2012, 09:57 PM   #4
Firebirdjones
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Re: low comp 454 block or high comp 396?

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Originally Posted by shipma2 View Post
hmm u may be right by putting a bigger cam in a 454, it would highten power and comp. i may look into that .
I forget what the original camshaft was in my 79 454, but I know it was tiny from the factory. It ran out of steam at 4500.
The performer camshaft really woke that engine up, and buzzed to 5500 pulling strong, that along with the performer camshaft was all an attempt to build more low speed torque (and it did). Those performer cams still have an early intake valve closing, perfect for low compression engines.

Honestly it could of used more compression and made more power, but it wasn't a horrible running engine for what it was. I had kicked around the idea of milling the heads for a compression bump, but since I towed alot, and it ran warm on hot days while towing anyway, (all detonation inducive issues) I decided to leave it alone.
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Old 06-03-2012, 10:02 PM   #5
shipma2
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Re: low comp 454 block or high comp 396?

the 454 in my truck i was told by the guy i bought it from had a rv cam (weither i can believe him or not for lying that it was the orginal motor ) idk if its true or not
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Old 06-03-2012, 10:15 PM   #6
Firebirdjones
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Re: low comp 454 block or high comp 396?

Hard to say without pulling it. Everyones idea of an RV camshaft may be slightly different too.

I guess you could say the Edelbrock Performer cam I ran was an RV cam, as it was rather small for a 454 by my standards (218/228 at .050 and .500 lift) It idled baby smooth just like the stocker did.

Actually the camshaft in my new HT502 is smaller and it's a roller
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Old 06-03-2012, 10:18 PM   #7
shipma2
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Re: low comp 454 block or high comp 396?

very cool, ya on top of the fact someone (wonder if it was the previous owner) put a 600 cfm edelbrock carb and a 454 lol. sounds like a nice setup you got there though
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Old 06-03-2012, 10:36 PM   #8
Firebirdjones
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Re: low comp 454 block or high comp 396?

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Originally Posted by shipma2 View Post
very cool, ya on top of the fact someone (wonder if it was the previous owner) put a 600 cfm edelbrock carb and a 454 lol. sounds like a nice setup you got there though
Oh I see, I still run the original Q-jet on mine but it's tweaked I never was a huge fan of the Edelbrock carbs (looks like a modern copy of the old carters) but I do like alot of their intake manifolds they make. 600 cfm is a tad small for a 454.

Thanks, it's doing what it's meant to do and that's towing the trailer with ease (dyno'd 537 ft lbs.) so I'm happy. I wish the 502 came with a little more cam as it's rather tiny for a roller (207/209 @ .050 and .480/.483 lift) but amazingly it pulls to 5500 nicely (redline is 5700 according to paperwork) but HP peaked at 5200 (377 hp) on the dyno graph. So it could stand to use a little more camshaft I'm still pretty sure it'll run quicker than the ole 454 did, I'll plan some track time when the weather cools later this year.
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Old 06-03-2012, 10:38 PM   #9
shipma2
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Re: low comp 454 block or high comp 396?

hmm very good
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