180 is way too small.
180cc vs 195's
Thread Starter
Pro
Joined: Jul 2006
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From: chiefland fl
180cc vs 195's
hey guys, im building a 406 for my '84, the "impersonator" motor i am copying used vortec 174 intake runners, then went to AFR 180 intake runners, had 525 ft lbs of torque, and 490hp, is that a better street/strip head than say......195 intake runners? will i lose a ton of torque? just want you guys to weigh in on this one. thanx, Bill 
Drifting
Joined: Feb 2003
Posts: 1,976
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From: San Antonio Texas
Those were the AFR CNC 180s which flow very well, but have since been replaced by the Eliminator series which flow even better. I think you'd gain everywhere with AFR 195s Eliminator Street head; which is a lot less expensive than the CNC version. I've heard who makes the Jeggs head but I forget. It won't flow like the AFRs though (280 CFM). You could improve on that Flat-tappet cam they used too; it's a pretty old article, especially if you went to a Roller (230/236). Top it off with 10-10.5 pistons, Headers, and a Single-Plane EFI intake. JMHO
Melting Slicks
Joined: May 2007
Posts: 2,382
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From: Kathleen FL
I have had 200cc performance iron heads on motors as small as 350 CI and they still did very well, even on a high rise carb intake manifold.
But with a smaller intake port head, you should still have slightly more torque on the bottom revs just because air port velocity into the intake would be a lot faster than that of a larger CC head.
Basically I'd get a head with the smallest intake port that meets the CFM of air flow for the intended power you would like to make. If torque is your primary focus, go with a smaller port head for increase air flow velocity.
But with a smaller intake port head, you should still have slightly more torque on the bottom revs just because air port velocity into the intake would be a lot faster than that of a larger CC head.
Basically I'd get a head with the smallest intake port that meets the CFM of air flow for the intended power you would like to make. If torque is your primary focus, go with a smaller port head for increase air flow velocity.
Le Mans Master
Joined: Mar 2002
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From: Castro Valley Calif.
St. Jude Donor '03 thru '26
This is just supposition on my part, but w/ 406 CID I think you'd maintain torque, and increase HP because of the add'l flow. I've got some older AFR 195s on my 421, and I dyno'd 504 at the rear wheels. Again, just my thinking, but 195 is still a smallish runner on a big cube motor 
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Pro
Joined: Jul 2006
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From: chiefland fl
i believe you guys are 100% right! I dont think i can go wrong with the 195's because of the CI's, I did as was suggested and stepped up to a newer lunati Voodoo cam with 489/525, (flat tappet) roller money isnt in the picture right now, my firebird sold YESTURDAY!! so im in more of a pickle to get the car finished on a budget, things sure go astray fast! thought i would have time since i didnt advertise it well, just sitting in front of my music store in small chiefland (hootersville lol) but i need the money for these heads and just ordered a Dewitts radiator, AFR's are nice cnc bolt on from the factory, but if i get a nice set of alum heads from a local speed shop, he can machine em out pretty close i think, and i can save about $500. (pays for the rad) this forum is the best, there are no smarter people out there than here! thanx.
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