318 Heads, #4343646

[bschubarg]

I just swapped cylinders. Replaced my #646 with a set of swirl, #714. My question is are the #646 worth keeping? They are 1.78 intake, open chamber. I will say this, these heads offered some great low torque combined with the cast 4bbl intake and headers along with a stock camshaft. Also, what I thought was strange, was that this block was casted in 1990, yet the camshaft is a hydraulic tappet and not a roller..... possible?

Anybody care to guess what, if any HP increase with the #714 heads?

Best Regards

 

[Mr Hemi]

The early magnum engines were just regular hydraulic lifters

 

[72bluNblu]

646's are ok. The should flow better than some of the earlier 318 heads, but the have a larger chamber volume. If you can deal with the open chamber, then they should fall somewhere between the early 318 heads and the 302 or 308 heads. They have 318 sized ports, but open chambers as you pointed out, and were being produced at the same time as the 302's.