71airgrabberRR
Well-Known Member
440 Source Heads
I was curious myself when these heads arrived. So I pulled an intake and exhaust valve to see just what the bowl area and runners looked like. I had a bare stock 906 casting to use as a comparison. I have to admit, I was impressed with the heads. They look like the runners are more of a straight shot than the standard 906 casting. Plus they have undersize 11/32" valve stems, and back cut valves, which help a little with flow numbers. The factory mopar heads all have 3/8 inch valve stems.
Plus I like the fact that they can be installed and painted the same color as the rest of the engine, sort of "camouflage" and sneaky. They look almost like the factory style heads when installed. You have to look VERY close to notice any difference. (which is very minor and nearly impossible to see when installed in the car with all of the accessories.).
Before I purchased this set, I compared the advertised flow bench numbers, and if memory serves me correctly, they outflow a trick set of 906's by about 30%.
So for me it was exactly what I was looking for. Another benefit of running an aluminum head is that you trick the engine into believing its running a lower compression ratio because of the additional cooling effect properties of the aluminum. For example a 10.5 to 1 engine behaves as if it was a 9.5 to 1 engine. Plus you have hardened seats and don't have to worry about running unleaded gas or adding an additive.
Hope this helps.
I was curious myself when these heads arrived. So I pulled an intake and exhaust valve to see just what the bowl area and runners looked like. I had a bare stock 906 casting to use as a comparison. I have to admit, I was impressed with the heads. They look like the runners are more of a straight shot than the standard 906 casting. Plus they have undersize 11/32" valve stems, and back cut valves, which help a little with flow numbers. The factory mopar heads all have 3/8 inch valve stems.
Plus I like the fact that they can be installed and painted the same color as the rest of the engine, sort of "camouflage" and sneaky. They look almost like the factory style heads when installed. You have to look VERY close to notice any difference. (which is very minor and nearly impossible to see when installed in the car with all of the accessories.).
Before I purchased this set, I compared the advertised flow bench numbers, and if memory serves me correctly, they outflow a trick set of 906's by about 30%.
So for me it was exactly what I was looking for. Another benefit of running an aluminum head is that you trick the engine into believing its running a lower compression ratio because of the additional cooling effect properties of the aluminum. For example a 10.5 to 1 engine behaves as if it was a 9.5 to 1 engine. Plus you have hardened seats and don't have to worry about running unleaded gas or adding an additive.
Hope this helps.
