Best flowing Factory Head - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Ruger · 10-08-2004, 08:17

ive heard its the 91AA

anyone got any info

this motor will be running stiffer valve springs, stage 3 crow cam and the usual intake/exhaust

besides the xr6 heads of course.

Axeman82 · 10-08-2004, 17:37

AU head to my knowledge..

Dan..

Ruger · 10-08-2004, 20:31

what about ea-el

considering i already have the cam and will need a different one if i get the au head.

jonbays · 10-08-2004, 20:51

Stock AU head has the largest valves, smallest valve stem diameter and flows 300hp so it should be the go but it has small ports and a nasty bulge between the valves so it can defintely be improved. EF have smaller ex valves but bigger ports. Either way both are fine for porting. If you want to bolt on a stock head the AU will be best but you need the rocker gear and cam to suit.

Spider_GT · 10-08-2004, 21:14

au is the best flowing i have a au xr6 head on my ed and yeah noticable difference

stockstandard · 10-08-2004, 21:51

I thought the eb xr6 head was the pick of the e-series flowing 320hp. E-series heads can be fitted with AU valves which are bigger than the non-xr e-series vavles and have thinner stems. EF/EL heads are a good starting point as well, mine flows just under 380hp with a port and polish and some valve work.

needfordspeed · 10-09-2004, 00:43

Quote:

Originally Posted by Ruger

what about ea-el

considering i already have the cam and will need a different one if i get the au head.

I've heard the best flowing eseries (non-XR) head is the 91AB head, that's what i've heard though I got no hard evidence.

jonbays · 10-09-2004, 15:56

Stockstandard is right the EB head is the pick of the stock heads it apparently flowed 320hp stock but.... is not as good to port as the EF or AU.

MustangNicko · 10-10-2004, 16:06

Whats the best flowing factory XR head?

jonbays · 10-10-2004, 16:58

Don't know to be honest but I am guessing EF.

It had the bigger ex 41mm valves like the AU but with bigger ports.

AU and AU XR6 heads are the same as far as I can see.

You still have to look at the stock 300hp flow of a stock AU head which is 225kw and think are you building the engine to flow this much cam injectors and ecu?

With my Dev3HL running stock injectors and ecu and 142rwkw say 200fwkw I haven't hit the limit of the head yet and of course higher lift gives me more flow than the stock head anyway.