My purpose in showing these is to help you understand cylinder head selection and why I use AFR on most builds.
The first group are larger CNC ports used on 400cid plus engine that can make the upper limits of street power, 600bhp. 

HEAD BRANDS	Results Order	Peek BHP	Avg BHP	Results Order	Peek TQ	Avg TQ	Results Order	4000 TQ
TrickFlow Twisted Wedge R	1	667	580	1	572	538	1	540
AFR 225	2	651	571	2	564	531	2	535
Jegs/Kasse	3	641	558	5	554	519	5	525
Edelbrock Victor Jr	3	641	566	4	559	526	6	520
Dart Pro 1	5	627	564	3	564	524	3	530
TrickFlow High Port	6	623	533	7	549	514	6	520
Pro Topline 223	7	603	548	5	554	511	3	535

This group is for higher RPM 351 Families of stroker engines. For lower speeds a 205cc port will prove better suited.

The motor used in this test made maximum power around 7000rpm.
You will see that top 3 power producing heads where close in peek power production.
This is due to these heads being CNC ported and hand finished, being done very carefully so as to be competitive in this magazine article.
This is so that the companies porting the cylinder heads would gain increased business.
You may buy heads that do not produce as much power, so these results are only to help you choose the best cylinder heads

The most important power production number for the street is low speed torque, as this is acceleration.
TrickFlow Twisted Wedge R, AFR and Victor jr where the leaders and any of these would be a good choice.
For peek torque the TrickFlow High Port came out on top with the AFR a close 2nd being down a  8ft/lbs, not much, but the worst head only made 23ft/lbs less.
Average torque the TWR first again with a 16bhp lead over AFR and 64ft/lbs over the Pro Topline heads.
Peek BHP is where the greatest difference show up and are directly related to airflow.
The TWR heads flows 8cfm more than the AFR, but 22cfm more than the Topline.

For torque the TWR would be the best choice, however being custom ported, the head you buy from your supplier maybe better OR worse.
AFR would be the 2nd choice for overall torque.

Horsepower is a function of RPM, meaning typically high horsepower motor do not do as well in the low RPM range.
Yet the TWR came out on top again.
AFR was again 2nd 16bhp behind.
While Topline came in last foe peek horsepower, the Trickflow High port head was last in average BHP.

If you are buying an off the shelf head, the AFR is the simplest choice, as buying the TFS TWR head requires a second purchase to have it CNC ported.

Stroker Engine CNC head porting is done by Pacific Performance Products, makers of Avenger Cylinder Heads.

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HEAD BRANDS	Results Order	Peek BHP	Avg BHP	Results Order	Peek TQ	Avg TQ	Results Order	4000 TQ
AFR 185	1	448	343	1	445	418	1	412
Ford Racing Z304	2	442	338	3	438	411	2	411
TrickFlow Twisted Wedge	3	438	335	5	436	408	5	401
Canfield 192	4	435	338	2	444	413	6	400
Brodix M2	5	434	337	4	437	410	3	410
Edelbrock RPM	6	430	332	6	428	415	4	405
Roush 200	7	390	313	9	412	385	7	400
Ford GT-40X	8	390	315	8	416	386	9	377
World Windsor	9	386	315	7	419	388	8	398
Ford E7TE	10	351	295	10	400	366	10	375

The AFR came out on top, but bare in mind this head is CNC ported whereas the are not.
This increases the price of the head over the other aftermarket brands, but only a few hundred dollars making it very good value.
The other aftermarket leaders will likely match or beat the AFR head if also CNC ported, but their final cost will surpass the AFRs by about four hundred dollars.

The motor in this test made peek BHP below 6000rpm. For a higher RPM motor a 205cc will prove more powerful.

The Ford Racing Z304 proved to be a surprise coming in second. this is understandable for horsepower as they had the largest Intake and Exhaust ports, but to come in second for torque shows these heads work very well.
Testing with AFRs 165 verse 185 heads done elsewhere showed that larger heads do not always loose torque.
This in part is why choosing the best head can be difficult.
Smaller ports tend to see port velocity increase more quickly than larger ports, however port shape also influences port velocity.
Testing on the engine is the only sure way of knowing.