The short story is that even the new Venolia pistons, the lump still hit the head. I had to hand clearance every single lump. Once the lumps were clearanced properly, i bolted on a 57 848 head (the larger of the 848 combustion chambers), a 59 848 head (the smaller of the 848 combustion chambers at around 79.1 cc and the head that is on the motor now), a 59 261 head at about 86 cc, and each head passed muster, the lumps did not hit. For many years it had been suggested to me that you could fairly easily put 302 rods in a 261 motor. Ask around, and you will find that very few people have actually done it. It took a lot more messing with and some amount of frustration on occasion, to get them in, so it is not as simple or easy as some have suggested. The biggest challenges that I see are first obtaining the rods, having the big end machined down, modifying rod bolts to fit, rebuilding the rod, cut down the bearings, and I was lucky, I had a friend who helped me make up the tool and could do the job, custom pistons to deal with the 7 inch rod as opposed to teh slightly shorter 261 rod, and clearancing the cam for the rod bolts, assuming flat top pistons. With the pop up, the biggest challenge was clearancing the lumps on the pistons. I understand that Ross has a pattern that does not require any fitting so If I was to do this again, and I might, I would probably talk to Ross. That being said, the 302 rods while heavy, are pretty nice rods. Coupled with a floating 990 pin and big block rod bolts, I would think fairly strong. Moreover, there is no question that this motor sounds and feels different than any of the 235s I have built over the years (a lot). Between the cam and higher compression, larger valves (intake and exhaust) and some basic head work and smoothing and a little enlarging of the intake ports, it sounds terrific. The 57 it is in was my high school car in the middle to late 70s and has not been driven on the road for many years now. It was in need of a good bit of structural repair (rust) to make it safe, which of course lead to having to clean, paint and fix up everything else (it was all in worse shape than I expected). This weekend, hope to have the brakes finished and maybe drive it a little bit. If it runs as good as it sounds (to me anyway) ought to be fun.
On another note, I can hardly believe how many people have viewed this thread.
Edited by mdonohue05 (06/26/15 10:57 AM)