Bob-Morton

Most of the discussions on cylinder heads lean more to the top end performance, 4500 rpm +. I am more interested in the bottom end, where I do 99.9% of my driving, 1800 to 3000 rpm. Although the '86 heads are not popular due to their poor flow characteristics at high rpm, do they produce more torque/hp at low rpm because of the "swirl" design around the intake valves? Anyone have an opinion?

Jfsram

Very few articles will directly address this due to most people want horsepower and flow increases.

I can give you a bit of a starting point. Look for flow velocity. This is generally a phsyically small port with alot of flow.
So a 300 cfm head with 140cc's and another head with the same cfm but it took 160cc to flow the same air. It will be travelling slower in the bigger port which generally equals less torque.

Force4

My stock heads on my 351w made 325 foot pounds of torque at the wheels with a stock cam. My modified heads (170cc Edelbrock performer RPM aluminum) made the EXACT same amount of torque but increased the HP by a ton. If your not looking for speed then just leave it stock.

luckythirteen13

if you want more low end torque, get gears

67mustang302

^^^ This