ls6 cam

[markjohnson]

I think a #143 camshaft would be a nice improvement to a 427-390HP engine. I've driven stock 427-390's and they run good to begin with but I've always considered hydraulic lifters as a poor man's rev limiter. If you would happen to change cams, fresh new valve springs would be well worth the small investment.

[TDW]

Thank you Mark. I think I will go that route.

[WILMASBOYL78]

There seems to be some minor differences in the advertised lift for the 143 cam. Some places I have read say .500 and the Crane info says .520. All the techy stuff I have read says BB motors respond well to more lift, especially with a good set of heads. Wouldn't it make sense to have a little more lift and keep the duration about the same? Thinking about building a 427 engine for a project and using the 143 cam, 12 to 1 comp, 074 aluminum heads, etc. Based on the input here about this cam it should be a winner. Comments??

wilma

[Chevy454]

The Crane unit is a true "blueprint" cam, which is probably why GM offers it...the others just try to get close, but they're all over the map. Been there, done that...

As for your future combo, our Y-Camaro is 12:1 with the 143, but 840s instead of 074s...and it's putting 430+ horsepower to the rear wheels, through stock exhaust manifolds in Pure Stock form...so decent power, I guess...

[WILMASBOYL78]

Thanks Rob for all the input on this cam and how it performs. Are you running the stock 163 intake on your car? Would you recommend an aftermarket unit that might perform better. Thanks again.

wilma

[markjohnson]

The stock hi-rise aluminum #163 is very hard to beat and just looks right on these cars. My '55 runs mid 11's with the #143 camshaft and a 1966 aluminum #069 factory intake. Basically the same as the #163 intake which is the long water pump version. The plenum is even still intact in mine. A fantastic reference book that goes over all of this is the "How to Hot Rod Big Block Chevys". It was published in the early seventies and was circulated for about 20-30 years making it fairly easy to find even today. A wise friend gave me a copy when I was 16 and it has always been my bible steering me in the right direction. It is a crime to not own this book if you love those Rat motors!

[TDW]

Mark..I just got that book. Your'e right, its full of good reading.

[markjohnson]

The book just stresses over and over again about how well designed the stock GM Hi-performance components really were. Most Supercars were built back in the sixties with mostly GM parts because the builders knew what worked and what didn't.

[WILMASBOYL78]

It is sitting next to my computer as I type this, grease stains and all. I have head this book for 30 years and the info is just as good today as back then. It is funny to see the prices they refer to for hi-perf Chevy parts. $25 for an L78 cam!!!! Man, those were the days.....

wilma

[Chevy454]

Wilma: our Y-Camaro races in Pure Stock, so the major hard parts have to be from the factory...so it's the run of the mill 780/163/840/427 combo...nothing fancy on my part...but as I tell folks all the time, the Chevrolet engineers have a gabillion hours into each and every part, so who am I to second guess them? This combo just plain works, and on a skinny tire it works better than my LS6 did as it will RPM better on the big end due to the stroke and the reciprocating weight.

A nice supplement to the "How To Hot Rod BBCs" book are the books by Ed Staffel (Max Performance BBC's and BBC Hi-Perf Interchange)...they take what you learn in the "How to Hot Rod" book and take it to another level...from ignition curves to compression mapping camshafts....pretty good stuff.