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Looking for  advice. Street cam , 2,000- 6,500 rpm, 400 hp goal

73 Mustang convertable, 351C 4V 1970 DOAE-N heads, Flat top pistons 1.668 pin height 10.4-1 compression, Romac 0203 damper, dynamically balanced, adjustable rockers guides hardened push rods, Blue Thunder Intake, heat riser blocked, Summit 750 carb, MHD ignition, 2" headers, Ram Air, Cam Research Valves and lifters. 5 speed TKO 600 with high rpm shift modification, 3.70 rear gear, Borla exhaust.

Looking at Crane H278-2..........or the BOSS 505 290/290 doing a custom grind with same lift as the H-278-2  .539/.534......or other suggestion.  I want to maintain good  bottom end and wide power band.

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I hoped there would be a bit more discussion about this, because I am looking for a new cam too. I read everything about the "George CobraJet Cam" and I think it's a brilliant idea, but I honestly don't understand why he picked these lobes specifically.

1. The Intake Lobe is a .875 Ford specific design, which George emphasizes. The Exhaust Lobe however is not, although there are "Ford Lobes" in the Bullet Catalog that are close and could be interchangeable in my opinion, i. e.

HF288/356   288  236  151   .3560  .000  CRA

which leads to

2. why does exhaust and intake valve need to have the same lift? Most cams including the stock Cleveland cams have more lift on the exhaust side. This leads to

3. what is the critical lift for a 4V Cleveland with Iron heads? I know it depends on the valvetrain components and the clearance between valves and piston. But lets say you have a stock high compression Cleveland and just want to change the cam (you would at least put new valve springs and lifters in it anyway), what is the critical lift?

If you take a look at the Howards lobe catalog on page 26 for the Ford specific .875 tappets nearly every lobe has more lift

It would be great if somebody could clarify these questions.

Thank you for reading and for the record I don't want to disrespect anybody especially not George Pence.

The lobe posted above is closer to the typical 290° on the exhaust side, if you leave the 114° LSA and the Lobe Centerlines the same, you would have 0.5°more overlap.

Also the hydraulic intensity is the same, so the only thing that can be said against this lobe is the lift. With a 1,73 rocker arm you would get .615 lift, which exceeds the .600. I lack experience if that lift is too much for a hydraulic flat tappet cam in 4V Cleveland but the Hydraulic Roller Cam George specified has .611 Lift on the exhaust side.

I am with George on the Intake side however. With the big port you don't need the long 290° intake duration. With it comes more overlap and worse "low end manners".

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