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Discussion Starter · #1 ·
I have a 1969 350 that was originally a 255 horse motor. I took off the 441 heads and will be replacing them with the 1.94 valve 041 heads.
My 69 camaro has a Muncie M21 and I think 3:07 gears in the rear end.
The original cam went bad and I was wondering what would be the best choice to use?
I want something that will give me a little more horsepower but also be great on the street, cruising etc.
I would like to know the proper way to break the cam in on a motor with a few miles on it.
Also the original lifters are very hard to remove. Is there any trick to removing the lifters besides maybe using a good set of vise grips?
 

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Probably CC's 270 Magnum or Isky's 270 Mega for starters.

Note, nothing fancy here at all, but if you want SOTA, then look at the 268 VooDoo.

pdq67
 

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Well here I go again relating my experiences with a Muncie and mid range ratio's particularity 308's to 3.31's. I imagine your looking at approx a 9.5 Static compression. and shooting for an 8.0 to 8.2 Dynamic Compression Ratio (DCR). Check out Patrick Kelley's DCR Calculator at: http://www.empirenet.com/pkelley2/DynamicCR.html

Here's the COMP CAM SBC Catalog: http://www.compcams.com/technical/Catalogs/106-07/122-167_226-227.pdf

A Muncie to a Mid Ratio Gears LIKES MARINE CAMS Period and nothing sounds better then a Marine cam idling or accelerating preferably with a 112 LSA. The 110 LSA may be better at the Strip. The 3.07 Ratio likes mid range torque. With them gears you will be moving too fast to take advantage of Higher Revving Lower DCR Cams.

With a 9.6 Static compression Ratio I would recommend that you upgrade to a Retro Fit Roller Cam either a Hydraulic or Mechanical Extreme Marine 112LSA Profile. You will not have to be particular with ZDDP Oil Content with a Roller but I still would use a an API SG grade on a Retro Fit Engine. This delivers a super wide Torque Curve, maintains Hi-Revs and very suitable for accurate shifts on a 4 Spd. Check out a Marine Cam profile with something like the XM264HR 264/270 advertised, .488/.495 112LSA. This cam will make that 350 a brute with the Muncie and 3.07 Gears. If you stay with Hydraulic Flat Tappet something like XM262H 262/268, .462"/.477" 112 LSA .

Remember the Longer the Intake Duration the Lower the DCR. Considering 1.94 Intake Valve and 3.07 Gears, I would not go beyond a 268 Intake Advertised with a 9.6 Static Compression Ratio. If them 041 heads are giving you around 10.1 static then shoot for a slightly Longer Intake Duration but keep the DCR between 8 and 8.2.

If the Block has not been decked run a Steel Shim Head Gasket to keep the quench to a respectable .044"

I not advocating Comp Cams as MOST Cam Mfgr's supply similar Profiles.
 

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Discussion Starter · #6 ·
I forgot to mention I will be using a factory "472" 69 Z28 high rise intake .............
Thanks for the suggestions so far.
 

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Agreed if he's got 10.1 then something like a XM270H 1600 to 5800rpm, 270 286 226 236 .480 .489 112° profile would be very nice with a DCR of around 8.15.
Sort of Agree...dont over cam for a street car...Iwould tend to go something a bit milder,
If u do find the engine is a bit over camed advance it 2 degs...so install with adjustable keyways...I prefer adjustable keyways to adjustable dowels
 

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Steps Yah! Install the XM270H-112 at 104 Degrees or run that XM264HR-12 264/270 .488/.495 112LSA straight up. If I had extra money for a Roller SetUp, I would choose the XM264HR-12 and spike the Gas running over 8.2 DCR. Man that would Haul with a 4 Spd and 3.31's - LOL. Crane makes nice Roller Billet Profiles with a Cast Distributor Gear but somewhat Expensive.

I run a 600Hp BBC with a similar Drive Train using a Donovan Cam Gear Drive and can dial in Cam Advance/Retard with a Mechanical Roller very simply but have to remove the water Pump. Someday I'll install an Electric Water Pump or a mechanical one to run off the extra belt drive groove in the Crank Pulley then perhaps run a Hilborn Mechanical Fuel Pump off the Donovan to a Faulkner FI Stack and use that extra Pulley groove to engage a Paxton but loose that Stock Look - My Engine Bay appears American Stock and not many can pick out where the 600 Hp on pump gas comes from: but I do Flag a WARINIG:




I'm really Old School - OH Humm! We are a sorry lot. Can you believe that Junk Yard L78 Dip Stick sells for over $400 on eBay - I was so impressed I built my engine around it :eek:
 

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Jeff that 292H-10 is great for the Strip and FAST Street with High Ratio Gears running an Auto Stall but Muncie to Mid Rear Gear Ratio's are all together different. I've a 327 with a Sigerson 296S Mechanical Flat Tappet that revs over 8000 rpm's as a Spare Motor and that's all it is. My BBC Mechanical Roller will rev 7000 rpm. With 4 Spd's you need to have control of Clutch Feathering and Shifts. Sure your Combo will Launch but a 4 Spd will run you down by the end of the Quarter or Top End. 4 Spds are a Driver's Ride and we attempt to dial them in for All Purpose - My goal is Respective Street Performance and HWY Dominance. It all depends on what you want. I like to Cruise without the Engine burning the rings or pounding the Valve Seats every 20,000 miles. I expect at least 100,000 miles between engine rebuilds.

Jeff, I respect you where your at but Please Look at Alternatives.

I'm getting Too Old and my IQ has Shattered - lol

PS: Consider the Holley 750DP with that Combo.
 

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Jeff that 292H-10 is great for the Strip and FAST Street with High Ratio Gears running an Auto Stall but Muncie to Mid Rear Gear Ratio's are all together different. You need to have control of Clutch Feathering and Shifts. Sure your Combo will Launch but a 4 Spd will run you down by the end of the Quarter or Top End.

Ya, I figured as much which is why I edited my post and included my stall and gear ratio. :)

I loved it in my car though.
 

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Please contact UDHarold and ask him to spec you a SB version of this BB solid lifter cam that he created for me.

278/249/161, 110/106, .618" gross lift and it need's .018" lash on both sides!

And say hello from ol' pdq67 for me!

I figure in a 10 to 1 CR'd engine it will pull like a freight-train!!

pdq67
 

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Thanks for the tip Ron but that engine is going to be turned into a 383 stroker, hopefully. When I have my plans laid out, I will post them up and ask for some opinions on the parts I've chosen and what could be improved. Maybe I cam PM you with some questions sometime, if you wouldn't mind helping a novice.

Jeff

PS: The only time I was ever run down in any race was by a blown or nitrous car. ;)

I used to love racing on Telegraph.
 

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I expect at least 100,000 miles between engine rebuilds.
Cripes!!!!!!!
I expect at around 120.000 miles to start to have a puff of smoke on start up due to worn valve guides...re do heads around 150,000 miles and MAYBE a rebuild 200 to 250,000 miles plus.

Even the wifes little toyota corolla shoping basket , at least 150 to 200,000 miles with only 3 cam belt changes and couple sets of CVs
 

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Right steps, get him to buy a Toyota for longevity!

THAT or run a 100 percent STOCK lo-po engine that would last like he wants.

pdq67
 

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Right steps, get him to buy a Toyota for longevity!
No The sb will last longer than the jappa...AND can have a few more rebuilds
Unlike the SB its not even cost effective to rebuild the jappa.
 

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Hey Guys: Don't expect a BIG CAM and 3.73 gears to get any more then 80,000 buzzing at 4G all the time. If I got 100,000 miles left in me I'll be Happy - LOL

My 84 Volve has 350,000 Kilometers on her - Aside from a couple of Timing Belts and Points it does not burn a Cup of Oil between Oil Changes twice a year. What a Great Engine and Drive Train.
 

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3.73 gears to get any more then 80,000 buzzing at 4G
Got a piont there...Im running 308s on 14" 235/60s
Oh and 11:1 compression with 105 octane fuel...Dedeicated LPG...and no special additives.
 
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