howdy, i've got a project truck. 1950 Chevy 3100 5 window. i'm turning it into a g***er type hotrod contraption. my question is this: i am looking at 30 x 10" Hurst cheaters for rear tires. i currently have 3.27 gears. what gears should i use? i'm considering leaving them in, or swapping for 3.73's, maybe 3.90's or 4.10's *** now for the details *** ch***is: stock frame. straight axle front end, ford 8.8" rear end. parallel leafs front and rear. lowered 2". ladder bars out back (soon). engine: 350sbc. .040 over, .100 dome KB pistons, 9.7:1 static: 8.6:1 dynamic, 200cc Sportsman II heads, full length fenderwell headers, Lunati cam - Street Master II 275 single pattern: 224/224 .477/.477 108LSA @ .050 blah blah blah. 680cfm Quick Fuel HR vac. secondary carb. jets= 70 prim. 77 sec. 6.5PV Edelbrock Perf. RPM intake. 1" open spacer. 80gph fuel pump. timing: 22 deg. initial, 35 deg. total. idle: 14" Hg @ 1000rpm ******: th350. stage II shift kit. 12" 2600 Raptor stall (Performance Auto) vehicle weight: 3,300lbs race weight with driver and fuel the reason that i'm considering leaving the gears @ 3.27's is i'm looking at supercharging my set up. i'll rebuild the engine to better suit a boosted app. but the output should be similar. the heads would remain the same. the cam would be a mild-ish street/strip nitrous HP type with duration under 230 @ .050. the blower would be a 142-177 type mini-blower. i have no idea how much power this current N/A set up makes. i'd guess around 350hp, maybe 375hp at the flywheel. runs strong with the current 26" tall radial tires. i have yet to take it to the ch***is dyno. i'm just curious what you guys think for rear gears and maybe HP numbers. thanks, Ben
you left out the most critical piece of info... what do you want to do with it? do you wanna drive it, race it, do burnout shows??? run it on the highway, drive it to the grocery store, trailer it to the track???
it's 99% street driven and will most likely remain that way. i dont have the time or money to race it right now. so considering its usage, it's a "street build", although i've been thinking of it as more of a "street/strip" overall. i want to drive it on the street to car shows, cruises, and the track when i go there. quite simply i have no access to a trailer. i need decent highway manners (e.g. not be winding to 4grand on the highway @ 60mph). so plain and simple, an effective street build that's responsive.
Tall tires, long duration cam = deep gears. Run 4.11:1 for starters and see if it likes it. That should be in your ballpark anyway.
Yep, that handy dandy link confirms it. This will allow his engine to tach at about the same rpm with 30"tire and 4:11 as 26"tire and 3:23. Plus, with a 2600 stall, the 4:11's are better suited at having the converter locked up on the frwy.
can't beat the 4.11s with an overdrive trans maybe T5 to start or 700r4 since you have an automatic and upgrade when necessary. I had a 40 with sbc, turbo 350 and 3.07 rear gear. It was good on the freeway, but BORING.
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