need a heads recommendation Compression related.
I lived in every place you listed for at least a year...except Gimli, but my parents live there half the year so I’m there quite a bit.
The only local fuel I have any great luck with is shell premium, I run it in everything except for the newer 5.0 Mustang my wife drives,she just runs regular co-op gas in that thing.
Even in my lawn equipment E87 goes bad in a few months or it gums up the carb jets in no time...I would not dare to even try it in my 9.5 comp 340 with the iron heads.
E87 goes sour faster than that, so I install stabilizer in everything. Shell gas comes, or used to, with stabilizer already in it.
In the car, I burn it up faster than it goes bad so it only gets stabilizer as needed.
You can tell how sour 87E10 is, by its color.
At 9.5Scr and with a cam at least as big as stock, your cylinder pressure might be sub150psi, and even with iron heads I would run 87E10 at that pressure.
My fuel system has never had trouble with this fuel.I have; 750DP, P4007040 Carter pump, soft steel 3/8 lines, EFI jumpers, a 1968 sender with a 3/8 pick-up added, and with and new factory 3/8 sock: no regulator. Tank is also a 1968 model.
This Holley is known to have a fat low-speed circuit. I left it alone.Maybe that is my saving grace. But honestly, I have never, in Manitoba, pumped a bad tankful into her. With every single tankful since the beginning, about 1999 IIRC, It has been business as usual.I think it still has those 1999 Champions in her. RC12YC or something close to that.
Maybe my car is just blessed...