Im pretty sure I'm staying with the 317s. I currently have 2 sets one on the burb and another on the spare engine that needs rebuilt. And since I'm putting new pistons in, I can easily adjust for the bigger chambers..
From what I've found, Richard Holder being one of the guys, and forum searches seam to back him up.
His 6.0/408 stuff and test of 317 heads on a 408. Though he didn't see what TQ could be made with the 317 heads with his 408/afr245 setup comparison
Stripped LQ4 with electric water pump does around 410/440 HP/TQ with factory intake and 1 7/8 headers and 317 heads..
All out the stock 317 heads support 525-550hp if CR is bumped.
The TQ test which makes most torque with a 408 with AFR 245 heads.
Lm7 cam 191/190 468" 450/522 HP/TQ with at least 500tq from 3400-4800rpm
Crane 206/212 500" 114°lsa cam 515/556hp/TQ with at least 500tq from 2700-5400. Unfortunately Crane cams doesn't exist.
I'll be keeping the CR, 87 friendly so 9.5-9.75 range. Rough plotting the 212/218 cam I'm looking at and 317 heads should put me very close to what the 206/212 and afr245 heads did.
Should end up somewhere around ~475hp and nice flat 500+TQ power curve, be happy on 87, pull 17-19mpg again and be pleasant to drive.
Scream shot of his 408/AFR245 head setup video
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