Totally agree on the split pattern cam.
I tried every factory FE setup I could in the Gonkulator - they all like a split pettern, usually 6 degrees, give or take a couple.
I think the 428CJ with a 14 degree split was a bit too much, but its better than straight pattern.
I pulled this airflow data off the TFS website.
Is this pretty accurate or is there more realistic data?
This shows Ex/In flow about 75%, which is better than most FoMoCo stuff.
Airflow Results
PowerPort 175
Lift Value Intake Flow CFM Exhaust Flow CFM
.100" 72 63
.200" 151 117 = 77%
.300" 238 171 = 72%
.400" 284 219 = 77%
.500" 317 239 = 75%
.600" 332 245 = 76%
.700" 338 249
Tests conducted at 28" of water (pressure).
Bore size: 4.250"; exhaust with 2" pipe.
https://static.trickflow.com/global/images/chartsguides/t/tfs-56417001-c00_pv.pdfBrent's values from Stan Weiss site for comparison:
4.155 bore, no pipe: (pretty close to TFS numbers except exhausts about 10% lower)
.100" 96 66 = 69%
.200" 159 120 = 75%
.300" 233 164 = 70%
.400" 283 197 = 70%
.500" 317 215 = 68%
.600" 333 220 = 66%