Some weeks ago I was reading a thread and this image was posted along the way. This alarmed me because the 1967 283 I have already had closed up has a crank flange like that of small journal 327 (forth from the left) but didn't register to me then. OK cool, it's a stroker 283 aka 307. Moving on to today in prepping engine to test run it on test stand to be sure it runs fine before dropping it in. During this prep work today I fab'd up some custom heavy gauge solid wire to depth probe #1 cly via spark plug hole @ TDC then @ BDC. Hmm!? 3" stroke. The crank when I inspected weeks ago for any bearing failure, clearances, and if crank had been turned. All looked good and std. std. in measurement. However I never bothered to look at casting number. So, a guess as to what's going on? Did GM do something different to the last of the 283's crankshafts?
What's missing is the chart is incomplete. Late 1965 through the end of 1967 production, the 2 barrel 283's started to recieve cast small journal cranks....GM's first cast SBC crank.Prior to these cranks, all SBC cranks had been forged. Almost makes you wonder if GM was experimenting in public by trying it with the lo-po 283 before using cast cranks in the large journal engines upcoming. The cast 283 crank has a flange very similar to the small journal 327.
What's worse is I had a heck of a time even finding any chart on the net. It just so happens the one I put up here it's tagged to the HAMB. Thanks for the info.
Another that is missing from that chart is the 262" engine 3.10" stroke crank used in 75-77 Monza.....but I cannot recall the shape of the flange, only ever seen it once or twice personally. Seems like it is much like large journal 327 or 350
The Jalopy Journal
