You could get the 425 hp L-78 in any "full size body" Chevy or the Corvette. There was also a 325 hp version, the L-35, that was available in the Impala and Caprice, and of course the 375 hp rated Z-16 Chevelle. I had a new 1965 Impala SS hardtop with the 425 hp L-78, M21 Muncie and 4.10 gears. It would run high 13's low 14's on the stock 8.25-14 tires. Bob
I read an article in HOTROD that said the L-88 was good for 560 ponies with a good tune and BIG diameter long tube headers... Not sure @ what rpm though...
I have an L88 cam and lifters I pulled out of the 325 hp 396 in a 69 chevelle, about 20 years ago. I also have a 454 block, cross drilled 396 crank, a pair of iron rectangular port closed chamber heads, a set of big rods, and a set of 11:1 forged .030 pistons. Now if I'd only get off my lazy butt and build my fake L-88.....
Lot of guys in my circle used to run the L-88 cam back in the seventies. Then I got ahold of a Harold Brookshire 256/263...
Ran a L-88 cam in a 396 69 camaro back in the 80s.Was pretty sluggish till mid track it came in and boy then did it pull..
needed the 4.56 to get an L88 going ...crower made a fortune selling a tighter cam for all the L78 and LS6 street cars , the GM cam vents too much static compression in case customers ran regular gas
I figured someone would have posted the specs for the L-88 grind on here by now, but no-one has, so here goes. PN #3925535 264/269@050 .560/.580, 113 And L-78 375hp 396 PN #3863143 242/242@050 .520/.520 114 Personally, I would be hard pressed to think of a situation where I would run an LDA wider than 110 in a N/A 396, and in most circumstances, I would be leaning towards 107 or 108, then duration according to rear gear and converter. The only time I would even go to 110 is if someone wanted to run a short cam in a motor with the factory 11/1's and wanted to close the intake a little later to bleed off some cylinder pressure. I have run the Ultradyne 256/263 .612/.630 107 in 396's and 427's it is a great 10" converter or stick cam for a hot street car. I have also run the Crane 256/264 .618/638 108 in a 427, it was pretty good too, but a little slower off the base circle, not as aggressive as the Ultradyne, and not as torquey. I have even run the Ultradyne 256/263 in my Ford FE. Real good 10" converter hot street cam.
I havent read this post from the beginning but I went to an auction a few weeks ago and watched a 396 4 bolt block, crank and a new set of pistons bring $2200. If it was me I would sell the short block keep the heads and find a 454 core to build a 496 out of. 100 more cubic inches will run rings around a 396 without winding it to the moon.
^^And piss-poor R/S ratios, RIDICULOUS peak piston acceleration numbers, beaten up bearings, main cap brinnelling, short ring stack hieghts, broken cranks, and all the other "stuff" that I have seen with that deal... Sounds great in the magazines, but no love here for the 496 deal, or 540's in std. deck blocks either. Even with a 4" stroke I did longer rods, 4.25 with a std. length rod? No thanks, I like my shit to live for a while.
I have run a 496 combo for 4 years now at the drags with a scat steel crank and stock length rods. Running it 6800 every shift and through the lights. 10.03 at 136 best. Runs just a strong now as when built. Must be doing something really crazy to do all of the damage you listed!!!!!
Friend of mine that raced in the same series(10 wide street car) as us (we were running a long rod 509, and I told him that if I was going to go bigger, I would build a 522 not a 540, as they were too fragile, and the bigger bore would let me go from the 2.25 to a 2.3 without shrouding the valve) broke a callies crank (way better than chinese scat stuff, just saying) in his 540, funny thing is, we had just a similar conversation to this one a couple weeks before, and he was saying the same thing as you. I almost felt a little guilty, like I had hexed him or something. Thing is, there no arguing with physics, as the R/S ratio gets worse, peak piston acceleration goes up. Those are the facts, and magazine writers that are trying to peddle cranks cant really do anything about that. Of course most guys have no idea how to calculate peak piston acceleration, and you dont read about it in the magazines, so I guess from an advertising standpoint it doesnt matter... Oh, and a little PS here. The guy with the 540 was a good buddy of ours, his car was 300lbs lighter than ours, and he never won a heads up N/A race against the "little" 509.
We are getting off the subject, but there is something to be learned here, so I will post this, then shut up about R/S ratio and the effect it has on bottom end stress. I decided to do a quick little comparision between the stock rod length 496/540, and the 6.535 rod 509 combo. First I calculated the negative peak piston acceleration for the 509 @ 7500, then I took the G number that generated (4176 negative G's) and calculated the rpm that the 496 generated the same number of G's at. The rpm for the 496? 7176 RPM. In other words, the bottom end stress in the 496/540 is the same at 7176 rpm as the long rod 509 is at 7500 rpm. The point of all this? When some magazine hack tells you that a stroker crank is going to last longer because you wont be spinning the motor as tight to make the same power, calculate the peak piston acceleration of the two combos, because he doesn't know what he is talikng about. None of this even touches on whether long rod combos make more power than short rod combos, that can be debated till hell freezes over, and a comparison that involves two identical engines with different rod lengths is not a realistic test, as the ideal cam timing and port volume is different for a different rod length. But there NO DEBATE as far as durability goes, its just physics.
Cam recommendation. I ran a couple cams through some dyno sym software, a slightly shorter cam on 110 (Comp cams XS282S), and the Crane 256/263 on 108 PN131311, both with 10.5/1 compression, they came in within a pound on cranking compression, both right around 180 and both cams were 4 degrees advanced.I am figuring this is about the max 92 octane will stand with a 3.73 gear and underhood air. The tight lda Crane has about a 10 ft lb advantage from 2500 right through to peak power at 5800, with the same cranking compression, thats what I would go with. With the dual plane, I would go with an annular discharge 850, and I did the sym with 1 7/8 primary headers. PS. This cam is not power brakes friendly. Figured I should mention that.
Hi I'm new on here I came across this page by looking 325 hp 396 on googlel GO TO A NHRA stock super stock combo, a divisional points meet, or a national open the cost is low and if you watch stock run and I guarantee you will see cars that run within the NHRA spec. and guidelines that will Blow Your Mind. Check it out it's racing with rules. Some rules.. NO! Ported heads, ONLY! Stock Lift on the cam Stock factory shipping weight. Stock carb and Intake for your cmobo. Stamped steel rockers. I don't think the 396 32hp is a bad combo. I have a 69 camaro with a 325hp 396ci built to NHRA stock eliminator specs. E/SA The index that you must run to qualify is 11.70 1/4 mile It weighs 3450 with a 3420 min. weight. I run a 3 SPEED 200 metric by Scot McClay with an 8 inch ATI T/C. Stahl headers & 4.88 gears and a stock 750 Q JET. Best ET is 10.98 @120 MPH. NOT the fastest in the class but respectable. SOOO... I'd say the 396 is not a SLUG! Here is a photo from the 2011 Brainerd MN NHRA div 5 points meet. Witch incidentally... I won! http://www.dragracecentral.com/DRCPhoto.asp?ID=228065&Filter=Year2011 I look forward to being a part of this forum. Thanks Glen P/S YOU SHOULD SEE THE 375 HP 396CI CARS!!!
The important thing here would be the pistons. If you have flat top pistons and open chamber heads, it won't work. You have some very nice components, the heads are about the best they made, the Winters intake is a great one for street performance, good power off idle to about 6k. You may want to pull the heads and see if the pistons are for open or closed chamber heads, Closed chamber heads will either be flat or have little bumps that look to fit the combustion chamer, open chamber heads will have a more spread out bump with valve reliefs. Sounds quite promising, if the pistons matcht eh heads, you will be quite pleased. ( assuming it was all assembled correctly, tuned etc..)
The engine in question is in the classifieds so I guess the original poster is never going to find out how it runs.
I have one of those 350 hp BB's in my 67 Chevelle SS396. I promise you it's not a slug. Of course to find out how it would really do I'd need to get rid of those old red line bias plys. Rowing the gears on the Muncie is probably one of the things every hot rodder needs to experience. My decision on a numbers matching restoration didn't include making the internals quite like they came from the factory..if you get my drift.
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