Will Trick Flow Heads work on a B block 400

IQ52 said
Oh sure, big cam, 7,000 rpm, 470 ci = big power.

But what if you have 400 ci, low compression, a .430" lift cam and 5,200 rpm? Surely that 270+ cfm at .400" lift with those heads will send that lowly 400 into convulsions and it will just shut itself off and make no power over the stock head.

Right?

I mean, way more head than the camshaft can handle. Useless!

Waste of money and time. That 400 needs smaller port heads! Maybe a conversion to install X or J heads on the 400 big block.

Bwaaaah, ha, ha, ha, ha..............!

Sorry, it's 5:30 AM here and I should be at the lathe working on the cam journal sleeve.

Good morning all!
Jim

Lol

There is a comp cam shootout where they test the XE line to see how much you gain with each step and how it effects idle and vacuum. (I get its basically a Comercial and where they don't change cr with each cam I get its gonna favor the smaller cams a bit.)
Still it valuable info most of us can't get anywhere.

The test engine was a chevy 383 with pretty good head to give the bigger cams something to work with. They were surprised that the 250 cam hit one hp per cid and the 2nd cam in the line the 256 hit 400 hp. I forget what overall out come was with the 296 probably 500 plus.

Big heads with smaller cam can get you a more streetable package even though your leaving a lot of power on the table. Seems to be the way automotive industry likes to make power LS new hemis. Not saying run 600 plus hp heads with a super small cam but seems like everyone has scared themselves with velocity talk that they strangle there engines.

318 engines are a perfect example of where most advise caution but that's fine if your goal is 300 hp and under but otherwise your gonna have to bolting on good flow heads if you want any real power.

I've noticed that the 2 hp per cfm rule doesn't seem to apply to most engines.
I'm guessing it's a race engine rule of thumb where your run 300 plus duration and 14:1 plus cr. But I have noticed that there's like a 1.8 hp per cfm rule with 285 ish cams and 10:1 ish cr I'm sure you could generalize it even more and knock off 0.1 for every 10 degress less cam.

I guess my ramble just saying there's more than one way to reach your hp goals. Might be a little better to add a bit more cfm and a little bit less cam for more streetable package. Example instead of the usual xe285h cam and 220 cfm heads for 400 hp maybe 250 cfm heads with a xe268h cam.