Thanks David, that's a big relieve. The photo's really help, too. I'm using Probe SRS model 12360 pistons, 1.280 compression height. These were ordered with a custom 30 CC dish, which gives me a near perfect 9.78 compression ratio with .040 head gaskets and 0 piston deck height.
You should be able to run regular-grade 87 octane pump gas with that static compression depending on the cam choice. My cam builds a lot of low-rpm dynamic compression, and runs 91 octane with 205 cranking PSI at 10.6:1 static compression. Full ignition timing with no det at 175°F average running temp. A 180°F thermostat (~195° running temp) would probably put it into det on a long pull. I probably cut it a bit too close, as a cruiser I could get a tank of crappy fuel on the road and limit my performance.
Rods are 6.125". I figured I would need to clearance the areas you described as well as the main stud girdle I plan to use. Or I may order the Probe one that is already stroker clearanced.
If you are going to use a girdle, I have one clearanced for a 4.17" stroke but never run. PM if interested in a good deal.
One more question: what brand and style of hydraulic roller lifters are you using?
Not. To maximize cruise performance (mileage) along with higher rpm torque, I used a flat-tappet cam. I chose it as the valve acceleration is higher (valve opens quicker) than a roller cam up to about .300 lift, giving deeper breathing at lower rpm with the different intake flow characteristics of a long-stroker. A very aggressive but noisy profile. Since I'm thinking of pulling-back from the edge a tiny bit, I may go roller to soften the valve train loads, even though performance may take a small hit. Even though the lift isn't high, those parts are working hard, and a roller should extend the lifespan to match the rest of the engine. Morel 5517 rollers under whatever branding would be a good choice for this application, and are a great value at around $300/set if you shop. There are other options, but you need a lifter that will not just last a couple hundred 1/4-miles, but 100k street miles, plus 1/4-miles.
[EDIT] Oops, you said hydraulic rollers - those are solids. I would strongly consider a solid for this use. Maintenance on solid rollers is next to nothing these days. And the noise... well, it's a performance engine.