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Discussion Starter · #1 ·
Looking to buy a house brand cam like summit or jegs. Mid 70s 454 781 heads. Stock compression 7.9:1? I'm looking for something I don't have to swap out Springs. Car might need 66 chevelle, 3.07 or 3.31 rear with wide ratio 4 speed. House brand cam due to low budget. Thanks. Jim
 

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i wouldnt use stock springs on any performance cam especially if its got a lot of miles on it. ls6 springs used to be inexpensive and im sure thier are some good used ones out there.
 

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Good quality valve springs are not that expensive and they are just good insurance for a performance engine. New cam needs new springs (not used ones), its just that simple. Just as important as new lifters . . . . . .
 

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Discussion Starter · #5 ·
Cam kit, add in Springs, may as well upgrade to 3/8" pushrods so that means new guide plates. New Springs should be measured for instalation height. So the $130 cam kit is starting to triple in price.
Then there's that fact it's a used set of heads... valve job? If your that far into it, why not buy a full kit and bore it? Turn the crank, resize the rods etc This is where people have more into a motor than the car is worth.
I understand wanting to do it right and a real shop would have to offer a warranty, but I'm just looking for a decent cam that will fit in a stock set of heads/Springs. Jim
 

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you better spot check a few springs to see what you have. im guessing they are 80 lbs max seat pressure. if all you want to do is putt around and have the car sound mean i guess it will work. you need a lobe that has a mild opening rate and around .500 max lift. i would run something like a 268 adv on 108 with the compression you have
 

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Jim,

Are you replacing the cam because the present one is bad or are you looking for an upgrade ? If you are looking for a stock camshaft then any of the stock replacement cams will work fine. Melling, Sealed Power etc.

If you are looking for an upgrade then you need to seriously think about valve springs. One of the problems with the stock springs is that they will coil bind at not much more than stock lift.
 

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Discussion Starter · #8 ·
I've got this 454 that I took apart about 7 years ago. So I just want to put it back together. I tossed the original cam and lifters. Last one I did I bought the 911-16 Springs which ran a bit over 100 bucks.jim
 

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1968 Malibu sport coupe, 489 ci. 590 hp 600 tq, RV T-400 Freakshow 3200 stall, 3.73 12 bolt posi
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I used a Summit/Crane .533 lift 108 lsa, 284 or 5 adv dur in an 86 454 with new lifters in a stock pp head and didn't have any issues but I only drove the car back and forth to a body shop about 10-12 blocks away, 1 nice big burn out...back glass fell out and exploded...wife was following...got yelled at but still had a big smile on my face cleaning up the glass, stock springs, new timing set adv. 4*, swapped heads to 063's with 2.19/1.88 and new .550 lift spring kit from comp products,had to cut the piston valve reliefs deeper, same cam kit.
 

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1968 Malibu sport coupe, 489 ci. 590 hp 600 tq, RV T-400 Freakshow 3200 stall, 3.73 12 bolt posi
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I think that Summit cam and lifter kit was around $130 but that was about 4 yrs. ago.
 

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Jim, would you consider a used hyd flat tappet cam/lifters/springs
 

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FWIW,Years ago,I installed a Crane 272H ([email protected] duration .515 110 LSA) into a stock 1977 454 with 781 heads. Did nothing else to the motor but I did use a 1970 low rise cat iron intake instead of the EGR intake. Coupled to an M20 with 3.31 gears,darn thing ran pretty good for what it was.
 

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you can get springs from competition product for around 50 dollars, single spring with damper around 100 seat pressure and 275 over the nose. Those will be lots better than stock which I have tested on some old heads over the years that was around 60-75 lbs on the seat, those kind of pressure on the old spring give up easy around 4500-5,000 rpms sending you into valve float.

I understand about saving money but at least throw down another 50-60 bucks for some springs and install them yourself, so you not coming back here saying your engine won't rev past 4500 or so rpms.

Nice cam for low compression bbc is the 272 crane cam, it has around 515 lift and something like 218 @ .050 110 lobe separation, going with a cam on 108 or even 106 would increase your cranking compression numbers increasing your low end grunt. This cam should get your to about 5500 rpms shift points with the spring pressure above.

Another thing you can do is take the heads off and for about 25 bucks more get the steel shim head gasket (.018" thick) and bump the compression up another .5 of a point, swap the springs over while the heads are off and you will be pleased with the extra torque and power just doing this on a budget.

Hope this helps.
 

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Discussion Starter · #14 ·
Dennis, that helps. Heads are already off and the pistons and crank is out too. Jim
 

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The reason to change the springs is to ensure you have enough spring pressure to keep the valves under control with a more aggressive cam, ie, more lift action in the same time as the the stock timeframe, and to ensure they allow the actual new valve lift or travel. Has to be verified as ok. Ugly things can happen if the parts are not matched up.
 

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Discussion Starter · #16 ·
Agreed on the springs. When I get ready I'll plan on Springs for sure.

I don't know why I try to cheap out, I know it's a bad idea. My rear-end for example. $400 for a running 2.73 12 bolt. $115 used 3.31 gears and open carrier, $75 for a Yukon installation kit (guy didn't need it) then I bought a used 3 series posi from member here $85 with shipping. He said I should at least replace the clutches, but if it's coming apart why not springs too right? And since I have to pay to have the gears installed, do I really want to install used parts when I can buy a ring and pinion with a new position and I stall kit for $550? And since we went this far why not new axles and studs?
Did I me tion there is nothing going wrong with the 3.08 ten bolt in the car now? Except it's a ten bolt open but the car only has a little 350.
And I do have a complete 4.10 12 bolt posi sitting here that might be a smarter idea to just use it and live with the revs around town and save a bunch of money. Jim
 

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Summit K1300 cam will be ok with stock springs. I just put one in and like it so far. I didn't get to drive it a lot before winter started.
 
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