I would like to know if anyone has a link or is willing to spend a little time on informing me on the afr 165 and the 185 heads. There hp and tq increases on a stock bottom end 5.0.
You will want the AFR 165's, because their smaller valve (1.90" on the intake) will clear the stock pistons with the majority of the popular off the shelf cams.
The AFR's are similar in performance, but they are more of a top-end head (6,500 rpm range) on a 302/306.
They are a great head!
I think AFR said that they gained 41hp from just a headswap on a 5.0L. I do not remember the details though.
Over your gt40p heads, I would expect a 20-25hp difference.
Tests conducted at 28 in. of water (pressure)
Intake valve size 1.090in./exhaust valve size 1.600 in.
Head Torque – 65-70 ft. lbs with 7/16” stud.
Rocker Stud Torque – 55-60 ft. lbs.
Rocker Pedestal Torque – 25-30 ft. lbs.
Intake Port Gasket – 1.200” x 2.000” w/ 3/8” radius
Exhaust Port Gasket – FEL-1415
Head Gasket – 1962-82 Fel-Pro 375-1011-1 or 1983-93 Fel-Pro 375-1011-2
Head Bolts and Studs – Standard
Spark Plugs – Autolite 3924
Intake/Exhaust Valve Angle - 20*
Angle Mill - .008” per cc
Flat Mill - .006” per cc
For the ultimate small block Ford street car, you've got to use AFR's all new 165cc emissions legal cylinder heads. Unlike some aftermarket heads, AFR's Ford head (CARB EO #250-3) fits all your stock components; no special parts are required! With 1.900 intake valves, 1.600'' exhaust valve, and combustion chamber volumes of 58cc or 6occ, and 69cc exhaust ports, AFR's new 165cc Ford head is perfect for 289 and 302 engines operating from idle to 6000 rpm. A 3/4'' thick head deck makes the AFR head ideal for nitrous or blower applications. Will not accept rail rocker arms. Hardened push rods required with part numbers 1400 and 1402. Note: 1986 5.0L must have piston notched for clearance.
Tests conducted at 28 in. of water (pressure)
Intake valve size 2.020 in./exhaust valve size 1.600 in.
Head Torque – 100 ft. lbs with ½” stud.
Rocker Stud Torque – 55-60 ft. lbs.
Rocker Pedestal Torque – 25-30 ft. lbs.
Intake Port Gasket – 1.280” x 2.100” w/ 3/8” radius
Exhaust Port Gasket – FEL-1415
Head Gasket – 1962-82 Fel-Pro 375-1011-1 or 1983-93 Fel-Pro 375-1011-2
Head Bolts and Studs – Standard
Spark Plugs – Autolite 3924
Intake/Exhaust Valve Angle - 20*
Angle Mill - .008” per cc
Flat Mill - .006” per cc
If you need the world's finest street/strip small block Ford head, check out AFR's all new 185cc intake port emissions legal (CARB EO #250-3) cylinder heads. With 2.020 intake valves, 1.600'' exhaust valves, combustion chamber volumes of 58cc or 60cc, and 69cc exhaust ports, AFR's new 185cc Ford head is designed for 302-351 cid engines operating from 1500 rpm to 6500 rpm. A 3/4'' thick head deck makes the AFR head ideal for nitrous or blower applications. Will not accept rail rocker arms. Hardened pushrods required with heads #1420 and #1422. High flow 2.020 valves might require aftermarket pistons notched for valve clearance. Note: 1986 5.0L must have pistons notched for clearance.
If you were working with a stock shortblock and HAD to have AFR heads, I'd go with the 185s and a custom cam. If you don't want to buy a custom cam, I'd go with TFS TW heads. I don't feel the AFR 165s are that great of an investment.
I am a huge AFR head supporter, I use a lot of them on my customers builds but out of the box on a stock bottom end 302 I have had excellent luck with the TFS TW.
Now if you want to notch the pistons the AFR185's are my head of choice