Hi All,

Looking for some advice on cam selection for my 65 Coronet. I picked up a good running 71 225 with an Offy 4 bbl manifold and a 500 cfm Carter AFB. The original engine is a decent runner but is gutless and a recent 700 mi road trip revealed some definite wear issues. I will be treating the new engine to a simple re ring freshen up. I plan on using the offy setup with a swap meet set of long tube headers. A .090-.100 shave of the head is also in the works. I am wondering what cam would be ideal for use in a big 3700 lb B body, with an auto and 2.94 Highway Gears. Obviously high rpm power is not the goal here but I would like a little bit more oomph. Something ground on a looser LSA would be cool to get a little rumble but I might be living in dreamland on that one, especially with a tight converter.

500-cfm carb and headers are high-RPM equipment…not a good match for heavy car with tall gears. Wrong tools for the job.

Put in a thoughtfully-chosen 2bbl and a set of Dutra Duals with an exhaust system configured like this, and a cam grind № 2106R from Oregon Camshaft and watch the gutlessness go all the way away and the car become a whole lot more fun to drive.

Even better if, instead of just deciding to take 0.090" to 0.100" off the head, you do the preliminary homework: measure your combustion chambers and then figure out how much to take off the head and/or the block to get where you want them to be with the head gasket you'll be using.

Even better still if you do the HEI upgrade with a distributor appropriately curved (by you or by DusterIdiot on here) for your car and driving conditions.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks for the advice Dan. I guess I got sucked in by the hot rod "cool" factor of those parts. I will definitely be doing some careful CC'ing of the head before hitting the machine shop. those RV OCG cams seem to be the hot ticket for street drivers.

I got a long ways on the stock short block in my '67 Valiant with the Offy intake and a Holley 390 carb, but the key to the performance was the ported head with oversized valves and a reasonable compression ratio.

You can make a good runner with the parts you have. The cam will need to stay mild for good torque. I would call Oregon Cam Grinding and ask for an 819 intake lobe and 818 exhaust lobe on 108° lobe separation and ground 4° advanced. Tight lobe separations have greater overlap and more pronounced idle characteristics.

If the headers you have are 1.5" tubes and they fit well then go ahead and use them, but you'll probably want to do something for intake manifold heat for driveability and engine wear. 1 5/8" tubes are too big.

The cylinder head needs help. Have you ever done bigger valves and pocket porting? There's a lot of performance there and without it the big carb and good exhaust won't live up to their potential.

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Joshua

forgive me if I mix up Loose and Tight LSA in reference to a 108 LSA being tighter than a 110. The Headers I have are indeed 1 1/2 " primaries. The thought of taking a die grinder to a cylinder head always makes me a little nervous but I'm sure I could do it.

The 500 carb is fine for what you are doing. It is only a 2 barrel until you don't want it to be. I have the 819 cam, 4 barrel and headers on my truck and it runs really nice and gets decent mileage for a brick.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

I definitely will be considering those 3 OCG grinds (2106,818,819). The RV-10 seems like a proven performer. although these are mild grinds, are there any valve spring upgrades nesessary? I have a set of 340 hp springs kicking around but they might be serious overkill.

2106R is the hot ticket -- not the same as 2106. No spring upgrade is necessary.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.