Is this cam a mistake?
 

'67 Firebird 400 Convertible, TH400, 3.08 rear. Engine being rebuilt by local engine builder. It's the original 400 with "670" heads. Rebuild includes balancing and blueprinting, some modest head work. Maintain stock 10:1 compression.

I want something a "little" hotter than stock, but not radical. Will be totally street driven and not raced. I was thinking a Summit 2801 or the "068" RAIII Crane blueprint with 1.65 rockers.

The builder suggested a Comp Cams PB280AH-10 (Part# 51-314-4).

Installed @ 106 centerline
Duration @ .050 Intake-232 Exhaust-237
Gross valve lift: Intake-.481 Exhaust-.481
LSA - 110

Is this too much cam? He insists it's not. From what I've read I'm worried. Should I be?

Thanks

For a 400 engine in a heavy convertible with auto trans and 3.08 gears, a horrible cam choice.:mad:

Only if you had 3.90 gears and a converter that stalls at about 2500 it would be a good cam.

Both of the cams you picked would be right on the money.:)

Yeah forget that comp grind. Go with the 068 spec cam and put on a mandrel bent exhaust system. Then get a Qjet done by Cliff and you will be very happy with it. Jim

I agree,the comp is too big.

Use the 068 blueprint,the 2801 is NOT an 068 "with more lift",they're quite a bit different cams,overlap,LSA,and the timing events are all quite a bit different,dont be mislead by those who tell you otherwise,look at the cam cards/specs.

If you want more lift with the 068,use 1.65 rockers.

The 2801 is actually "smaller" than the 068 (the 2801 is between the 067 and the 068 if you ask me),and with the 670 heads the 2801 will be marginal IMO,ask me it has the potential to build excessive cylinder pressure in a combo like yours.

JMO.

"Is this too much cam? He insists it's not."

Does this guy know ANYTHING about Pontiacs or is he just a Chevy guy?

Personally, I'd keep the cam, add Rhoads lifters and swap your crank for a 3" main 4.21" stroke crank. You'll love the torque. :D

And don't forget the dished pistons.

I'd run the Summit 2802 or Crower 60916 and a high quality 2400-2600 stall converter. Those are the absolute biggest cams I'd run in your combo.

I'm going by his shop and telling him I want to go a little more mild and suggest the Crower 60916. I talked to Cliff yesterday and he was a huge help.

Thanks.

Paul, I have the same car as you and I built my'n the way Cliff suggested and I am very happy with the results. Most impotent is to 0-deck the block.

My car runs 185 DEG all day long on 91 octane. If you have any other questions let me know. [email protected]

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