new 9" recommendations

skaz

Well Known Member
Supporting Member 1
#1
so im biting the bullet and buying the 9" from quick performance for my 61 bubble,what are your thoughts on
gearing currently sbc stroker dynoed at 425 hp 480 torque linked with an m20 stick 28' tall tires 275 r60 15 ,i know its a wide ratio but in layman's terms
i know the 350 gear (they offer) will be ok for the occasional hwy trip but is it enough for some balls in the city? or should i move up to their 370? if i go lower than 350 will it be a real dog in 1st?..just wondering before i hit the buy me now button
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#2
I'd go with the 3.70 if using the 28 inch tire,3.50 for 26 in.or smaller.70 mph will be 3,180 rpm with that 28 inch tire.Without knowing exactly which cam's in that engine,I wouldn't go much taller.You say 420 hp,but at what rpm?More importantly at what rpm does that 480 ft.lbs. of torque occur?
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
#6
That 5600 has to be the hp peak,the torque peak should be in the 3500-4200 range for a 420 horse 383.If the torque peak was 5600 that car would need a gear in the 4.88-5,.13 range to be remotely streetable.
 

Skip FIx

Well Known Member
#8
Let me know what you think of the housing, I had on old 9" pumpkin I had rebuilt with a 3.50 for my 64 409 project. Shopping housings now want a second upper link. Not sure what brake choices to use either.
 

Iowa 409 Guy

Well Seasoned Member
Supporting Member 11
#11
Brian's car's are way more fast than me, but my Quick Performance is a good unit also. You'll be happy with it. One thing you might think about. I ordered mine an inch narrowed on each side for better tire clearance.
 

skaz

Well Known Member
Supporting Member 1
#12
yeah was thinking about that!
will 1" narrower allow me to dump the exhaust behind the back tires?
i was thinking maybe 2"?...............275 r60 15 tires now
 

skaz

Well Known Member
Supporting Member 1
#19
funny how my wife's not as excited as me about the new 9" diff........$$$
.............got great service and a few extra (by mentioning this forum) from quick performance
went with eaton true trac posi 350 gears ...axles rated for up to 600 hp ........thanks again to all
.i will be forwarding some savings towards this forum..................cheers ................gord (skaz) winnipeg
 

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