update :
here's a little video of the 273 commando running thru the gears . "not a beat run sorry" . everything is running perfectly the way it should . I did down size to a stock 500 cfm afb carb after this video . and it ran much better with the 500 cfm than the holley dp 650. This new engine sounds much different than the last engine that came up with bad bearings .
In this new rebuild commando 273 , it has the 10.5 pistons vs the previous engine that had the 8.8:1 flat tops and a big erson cam 510-286 with no compression . now a ld4b vs the previous ld340 , clean up ports and gasket matched the 920 closed chamber heads .......
.... when you shift between gears with the new 10.5 engine it sounds like a harley motor cycle now .da da da da da when you shift between gears , like it has a lot of cavenging effect thru the headers . maybe you can hear it in the video. long tube 1 5/8 hookers into 2.25 head pipes the to 2.25 flow 40s' in and out , dumped before rear end. new cam is a isky t-3 455 lift 260 dur. 104 lsa with 2 degrees built into custom grind cam , 2000 - 6400 .
I think it sounds more like a harley now because of the higher compression or could use some quieter mufflers / x-h pipe, what do you think ?