i was wondering with the mods i heave on my engine(see signature) what gears should use(i have a 700r-4) i am considering either 3.73 or 4.10 what kind of milage loss is experinced with 4.10's over 3.373? in over drive and locked up what rpm will the engine turn on the highway? with 3.73 then 4.10's please help dont know witch to get?

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89 firebird formula


360 10:1compression (350 .060 over)/fully balnced and blueprinted
comp cams xe262 cam
performer rpm intake/port matched to heads
#1405edlebrock 600
sportsman 2 heads 64cc 2.02/1.60 valves 200cc intake runner/cnc pocket ported
msd 6al/msd8.5 super condutor wires
h.e.i. proform 50,000 volt vac. advance ditributor
700r-4 with 3.08 first gear and 3.23 posi 7 5/8 rear end.
b trans shift kit(will kill shifts...suck dong!!)
shorty heddman hedders with custom 3" pipe y-pipe back(no damn cat!) with 40 series flowmaster!
griffin daul1" core rad.cutom fabrication to fit(but no cutting )


future mods: 406 roller REALLY REALLY REALLY RADICAL!!!!!

 

I'd get the 3.73s. If you're going to drive on the highway at all you will kick yourself if you get 4.10s. Go to the calculations page on this site and you will be able to calculate the RPM you will be turning at highway speed with different gear ratios. I don't think you will like what you see when you type in "4.10".
bsa

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"If they do not run, Then they will die." - Stonewall Jackson
#3
'87 IROC, 355 TPI, Converted to SD, 700R4, B&M Megashifter, 3.42, Trick Flow Twisted Wedge Heads, Edelbrock Intake, Accel Runners, Comp Cam, Crane Gold rockers, Lucas 24# injectors, Edelbrock headers, Flowmaster 3'' exhaust, Mallory Ignition, Transgo Performance Shift Kit, Corvette Servo, 2,000 Stall Torque Converter

 

Just went and did the calculations. Looks like you will turn a little over 3000 RPM at 70 mph.
bsa

 

thanks for the replies so far so what do you guys with carbed trd gens run 3.73 or what ? im looking to "hit the bottle" in the future with a new comp roller cam that neeeds a 2800 stalland 3.73 gears. but untill i get the money *(oh about 3-5 months) i will have the mods in my sig. and need better gears than the weenie 2.73'sthe 4.10's are out because i got a reply saying i'll turn 3000rpm at 70mph......screw this! no way!!what would i turn at 70 in o.d. locked up with 3.73's?

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89 firebird formula


360 10:1compression (350 .060 over)/fully balnced and blueprinted
comp cams xe262 cam
performer rpm intake/port matched to heads
#1405edlebrock 600
sportsman 2 heads 64cc 2.02/1.60 valves 200cc intake runner/cnc pocket ported
msd 6al/msd8.5 super condutor wires
h.e.i. proform 50,000 volt vac. advance ditributor
700r-4 with 3.08 first gear and 3.23 posi 7 5/8 rear end.
b trans shift kit(will kill shifts...suck dong!!)
shorty heddman hedders with custom 3" pipe y-pipe back(no damn cat!) with 40 series flowmaster!
griffin daul1" core rad.cutom fabrication to fit(but no cutting )


future mods: 406 roller REALLY REALLY REALLY RADICAL!!!!!.with lots of NOS

 

My car runs 2700 at 70 with 3.42 gears and 245/50R16 Tires if that helps out. I didn't want to turn any more RPM's than that so I put 3.42's in instead of 3.73. 3.42 are MUCH better than the 2.73 I used to have.

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91 Camaro RS 5.0L Black Convertible 700R4
** Added so far **
*GM Wonderbar,Alston SFC's,spohn LCA's and Panhard rod
*Turbo City Inj Spacer
*Dual Snorkel Air Filter
*March Performance Pulleys
*GM 3.42 Gears with OEM Zexel POSI
*Edelbrock headers
*3" High Flow Cat
*3" Dynomax Exhaust
*Walbro 255 lph Fuel Pump
***Future 330hp Vortec Crate with LT4 hotcam and 454 TBI

 

heheh yeah i am going with 342's myself... puttin the whole new rear in saturday... wee disk brakes too!!

steve