Thinking about AFR185's or 165's

[BlueMonster65]

well i went to the dyno shop earlier this year and was surprised to see that my 65 only put down 213hp and 268trq to the rear wheels. desktop dyno sugested 320 at the flywheel, working backwards from my dyno numbers im at about 284hp flywheel with a 25% drivetrain loss. (its a C4 and 8") i think some of it has to do with it running a little rich. and some of it i'm sure is due to the restrictive heads. i'm running 68 302 heads with 1.94/1.50 valves. Roller rockers & screw in studs w/ guide plates but no port work or any other tricks. i have a crane powermax272 cam it is a split duration cam 216/228 and .484/.512. its nice but i believe the heads are restricting the top end. i am considering the AFR185's for repalcement but i am not sure if those are too big and maybe i should go with the AFR165's? if i plan to build the 347 i think the 185's will be better but i wonder how much the torque will suffer if i put them on my 306. anyone using either of these heads? if so i could use some advice, thanks.

 

[10secgoal]

I have a 302 .40 over with the 185's and an x303 ford motorsport cam and other goodies. I don't think they are to big if you make power to 6k or more. I only shift at 6100 and they are fine. They don't lack in in the low end either. The motor made 75 ft/lbs more than hp. They are well built heads all around. I would get the 185's if you plan to change the cam or go to a stroker in the future. If you want to keep the car the way it is with cam and all, get the 165's. Either one you get, heli-coil the header bolts before you put the heads on. Hope this helped.

 

[2bav8]

The biggest problems with the 185s is P/V clearence. The 2.02 valve won't clear without flycutting.

How long till you build that 347? Might be better off leaving the motor as is and start saving up and do the 347 right in the future.

BTW, 284 HP isn't that bad for such a small cam IMO.

 

[BlueMonster65]

will i have to flycut the pistons even with the low lift cam?
the real problem i have with the 347 build is that i will have to beef up the rest of the drivetrain to handle the additional power. i didn't think it was too bad either but then the new mustangs with the DOHC engine's were putting down over 300hp at the wheels with no power adders. just bolt ons.

 

[10secgoal]

It's really the duration that becomes the problem. Beefing it will depend on how built that 347 becomes. If you get stupid, like I'm going to, then yes. If you put out 450 to the fly, you will be alrigight for a good while. As long as no slicks go on the car and you don't get to crazy on the street.