Technical technical sbc dists

first of all I am 74 yo started working in sevice stations and garages in 1964. I have been a sbc fan all my life. but what I did not that the 265 had a different dist than later models. whatyear did this change? I had a 56 210 back in the day but it had a 63 327 in it. just wondering thanx Tom

 

about 1960 I believe was when they lost the notch on the back of the cam shaft. That would have been when they changed the distributer. Prior to the cam change the distributer needed to be clocked correctly to properly oil the top end.

 

57 was the first year of the new distributor that has the "window" cap. Then they switched from cast iron to aluminum, in the mid 60s.

 

The 265 had a smaller diameter distributor and cap, and the points did not use the Allen screw adjustment and the window in the cap, that came with the ‘57 engines, but the 1957 Hi Perf engines still used the small distributor. The advance weights in the small dist. were under the points plate so it was not as handy to fine tune the advance rate on those.

 

They were handy when installing SBC's in place of those old flatheads, gave you a little bit more clearance at the firewall than the later distributors.

 

Other than material, is there any performance difference between cast iron and aluminum distributors?

 

It seems like the bushings wear out faster in an aluminum housing, and then the distributor can be repurposed as a priming tool. I haven't seen too many cast iron distributor's with wobbly shafts.

 

thanks guys for the answers. I can't believe I didn't Know this but at my age I suffer from CRS the reason I even asked I was watching anIrontrap grage video and matt was putting points in a 265 dist and I noticed it Tom

 

Not really, not counting the Hipo versions.

Didn't the early small dist have clips to hold the cap on and the window has the spring loaded screws/bars/J hook?

 

Yes to the clips @1oldtimer .
There is a little known variation that was in the 302 Z28 distributors, they had a specially ground breaker cam said to help prevent point float. Also, for the L-88 and ZL-1 engines Chevrolet used cast iron bodies, did they agree with guys like Jenkins that said those were more stable? That always sounded like a stretch to me.

 

Some searching brought up this 2014 thread on the Tri 5 forum. Scroll down to post 9 by Farm Boy and you will find your answer (s) 265 Intake & Distributor in 327? | Chevy Tri Five Forum
I knew that there were a couple of differences between the 265 distributors and the later distributors but outside of the cap and rotor I couldn't remember what.