This is topic c4/rearend gears in forum Tech Talk at Northern California Ford Owners  .


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Posted by BlowN67 (Member # 4229) on :
 
whats a good rearend gears for amostly street drivin car with a c4. 285/35/18 tires on rear.
 
Posted by 50DADDY (Member # 3076) on :
 
Just for reference,i had 4.10's in a 12 sec. street driven Capri.It was horrible!Couldnt hit the freeway much,and when i did the motor was singin.Had to roll in the granny lane and still revved to high for my comfort.3.73's would probably be more bearable.Just my .02$.
 
Posted by BlowN67 (Member # 4229) on :
 
i was actually thinking in the 3.08 range or maybe even 2.73 i dont its something new to me never really had auto's
 
Posted by Blind (Member # 3052) on :
 
my brother in laws maverick has a C4 and 3.00 gears from factory, seems like a good match if you have a nice stall to get it moving.
 
Posted by Duncan Motors (Member # 7045) on :
 
325 is a good gear u might get a away with a 355 or somethin close cause of the 18 rims. just my thoughts. had the same set up with 245 45 17 and like it dont rememer the rpms at any speeds but 120 plus and the motor never went over 45 i think or it was close.
 
Posted by BlowN67 (Member # 4229) on :
 
i'm thinking 3.08's would be good cause my ultimate goal witht he car will be a street drivin turbo setup
 
Posted by 306mustang (Member # 9204) on :
 
am gonna have some 3.08s for sale for cheap after i get some 3 73s for my cobra
 
Posted by BlowN67 (Member # 4229) on :
 
acutally will be looking for a complete sn95 rearend soon here
 
Posted by Stangs R Us (Member # 4495) on :
 
3.27 / 3.08 either way
 
Posted by racsirx (Member # 1710) on :
 
26" tall tire-3:27 gears
 
Posted by 87TURBO (Member # 9257) on :
 
i also have a c4 and i recoment 327
 
Posted by BlowN67 (Member # 4229) on :
 
i will be driving it a 105 mile round trip when i do drive it so low rpms on freeway would be nice
 
Posted by onesicklx (Member # 285) on :
 
i run a c4 with 27" tall tires and run 3.27 gears...good luck
 
Posted by BlowN67 (Member # 4229) on :
 
quote:
Originally posted by onesicklx:
i run a c4 with 27" tall tires and run 3.27 gears...good luck
do u have any mph to rpm's u can share so i can make some judgements on which to go towards
 
Posted by uncle bill (Member # 3953) on :
 
john, go to tciauto.com their website has a racing calculator you can punch in your specs and get the info your looking for
 
Posted by BlowN67 (Member # 4229) on :
 
quote:
Originally posted by uncle bill:
john, go to tciauto.com their website has a racing calculator you can punch in your specs and get the info your looking for
Those are some great calculators. Thanks [worship]
 
Posted by wilit (Member # 3367) on :
 
I've got a C4 and 3.08's in my '68. With 245/45/17's it runs about 2500rpm at 60mph. 70mph is about 2750-2850rpm.
 
Posted by BlowN67 (Member # 4229) on :
 
ouch really... this is suckin big time. i guess a c4 isnt really made for daily driving.
 
Posted by wilit (Member # 3367) on :
 
quote:
Originally posted by BlowN67:
ouch really... this is suckin big time. i guess a c4 isnt really made for daily driving.
I've got an AOD in the garage, however, I plan on moving up to 3.73's. I figured I'll probably be turning about the same RPM's per MPH with that combo.

As for daily driving, I drive mine to school and back every Wednesday. Its about 35 miles round trip and I get about 16mpg with a stock '85 longblock and basic bolt-ons like an Edelbrock intake, carb, and long tube headers.
 




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