So what would you pick.. its going to be very Interesting lets see..... :)

[Herr_Poopschitz]

But will a .020" difference in factory bore size even be noticed? I think we need to be looking at numbers in the .100" range - like a 413 vs. a 440 to possibly make that case. Even that might be a stretch. Also a good head shop can blend the chamber to make up some lost flow. Valve angles of the 426 hemi on the "small" 4.25" bore seem to fix whatever flow problems there might have been on that block so I'd put more stock in valve placement (or maybe porting) rather than a small change in bore size.

Yes it will make a difference. Air and atomized fuel see a few thousandths as a huge gaping hole. Flow a SBC or SBF head on a 4" fixture vs a 4.030" and they'll pick up cfm. An Edelbrock designer told me shrouding is why they went w/ a 2.20" intake valve on the Victors over the more readily available 2.25". It's why an LS3 makes significantly more power than a similarly built LS2 w/ 821 heads w/ only a slight increase in bore. There are plenty of examples out there...

Blending the chamber is not the same as deshrouding the chamber. Even deshrouded, the limit is still the cylinder wall.

Sure there are other things that have a 'greater' effect, but as you well know, EVERYTHING MATTERS...neglecting one thing in your engine program allows others to win.

 

[68 HEMI GTS]

agree wedge heads are pretty sensitive to bore size. alot of times ill even pull the bore around where the intake valve opens with a grinder to match the cylinder head (if needed) above the top ring. thats always a good question to bring up when someone gets huge flow numbers on a head. what bore size was if flowed on.
the canted valve heads and hemi's don't really suffer nearly as much. like stated, a hemi will flow like gang busters on a 4.250 bore.

 

[383man]

I was curious as to how other feel cause i will be using a 440 with the 4:15 crank and that is because i already have parts for a RB Block plus my TTI Headers are for a 440 motor with indy Heads so i am going to use what i have it makes more sense then buying a new intake and headers and so on..Just my two cents...well maybe in my case 1/2 cent... LOL

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Ain't nothing wrong with your combo ron seems to run killer i would be happy as a PUPPY WITH TWO PETERS... LOL

Thanks for the kind words. Ron