Hi, have queston maybe someone can answer. Have 68 327, 30 over with a comp cams extreme 448 lift. Have one 291 (2.02/1.6) head 1967 cast. Also a 461 head (2.02/1.6) head 1966 cast. Would I have any problems using these 2 different castings on my motor? The pistons have a slight dish.

Thanks

Only if both heads cc the same so that their chambers are matched to keep from varying each banks CR.

BUT I would pick up a matching head whichever one you can find if it was mine b/c the chambers are shaped different between them.

Next is that I would verify my pistons deck volume and then run it through a compression ratio calculator like is over at the ROSS Racing Pistons site.

I say this b/c the pistons should be a down in the hole of .025" if not cheap rebuilders that are lower. This and the should be right at 66 cc chambers for big valve stock double hump heads along with whatever headgasket you want to run will need to figure out to be in the pump gas octane range to run right with whatever cam you choose. I figure 9.5 to just below 10 to 1 static CR. with cast-iron heads..

I would then use a dynamic compression ratio calculator and pick a cam so that I came up with from 7.75 to just a schosh under 8 to 1 dynamic/effective CR. Again for pump gas use is all..

One of the "Boost Calculator" sites has a "Effective/Dynamic Compression Ratio Calculator" on it that I use as well as Pat Kelley's great site that you get to by his sig.

Hope this helps.

pdq67

I have the same dilemma. 1 68 291 head and I believe a 66 461 head both 2.02-1.60 valves but both have been machined for screw-in studs and guide plates.

maybe you guys should swap a head? Then you'll both have a matched set...