Hi guys, wondering if any of you have experience as far as pros/cons of between running these stroke combos....just studying my options at this point:
my goal: 450~500 hp, turnkey, torquey, E10 (91~92 octane) pump gas friendly - nothing outrageous, just a street cruiser.
going into my AAR with auto and 3.91's....power brakes also.
A 4" stroke would easily get me to my power goals, I'm just thinking with the 4.125 stroke it would be that much easier, and would give me the option of a milder cam?? What I don't know is if there are unknown drawbacks with such a large stroke.
Block is just a garden variety 360 (late '72 casting date)...unfortunately, I found out it's already .040 over after tearing it apart.
We'll see how good/bad it looks after I sonic check it.
Prices of rotating assembles are relatively close of either stroke - so the $$$ won't be the deal breaker - I'm just afraid of the unknowns - Thanks for any input!

You're only talking about 12 CID difference between the two. I don't think you'll really be able to make the cam "that much milder".

I personally can't see that in that type of application the extra .125" being worth it. From what I can tell most of the 4.125" cranks are more expensive. Untill they come down to the 4" price level, you probably won't see many of them...

for the sake of conversation, let's assume there is no price difference between the two.......
the more I think about it, yes, I agree, it really wouldn't be "that much milder".

The custom pistons are where the higher cost is involved, but if you do a "basic" custom it's not too bad, but problem with me is, when it comes time to fill out order sheet on a custom piston I have hard time staying "basic"

Adding .125" of stroke is just going to move your powerband down a few hundred RPM & add ~ 20 ft lbs of TQ due to added CID.

I did a 4" stroke in a 71 360 block and in my opinion the rod bolt clearance notches at the bottom of the cylinder were kind of close to the water. I know for a fact I was using a 2.100 chevy pin and I think I had an Eagle rod and it probably had a 7/16 bolt. It's been a long time ago before anybody was doing it and there were no kits or mopar cranks etc. Eagle rods just came out then too for SB chevy.

So, if you do not have an R3 block you better be carful when you grind. I just did the welding rod down the water jacket pinching with my thumb and then slid it down inside the cylinder. Maybe my perceptive was wrong, but it looked close. Many say it is a non issue.

it will depend a lot on block/rod combo my X block with Scat H beams with 7/16 bolts cleared with out any grinding at all.
I did go ahead and grind a little anyway because I just wanted a little more clearance than what was there but they did clear to begin with.

The notch in the bottom of this 4.030" bore was minimal
using a 4.125" stroke with 2.00" SBC rod. I wish I'd
taken a better picture of the notch.

Bob weight was under 1800 grams and revs like a dirt bike.

If cost is not the factor between the two choices,go for the longer stroke.In a street car,you can't really go wrong with more torque.
Less convertor,gear,and it still pulls like crazy.
Just watch it on your choice of cams,these longer strokes can eat up a lot of duration and still idle well,talk to an expert if need be.