REAR END estimate

[69NovaKid]

i wanna go faster - or well quicker, i have a 10 bolt with an 8.5 inch ring gear with a 3.42 ratio and i was looking to bump it up to a 3.73 but a question or two is - does anyone have any estimate on how much it would cost in total to get the ring and pinion gears changed out? - and how would it effect its streetability- or 1/4 mile times?

[silicon212]

Originally Posted by 69NovaKid

i wanna go faster - or well quicker, i have a 10 bolt with an 8.5 inch ring gear with a 3.42 ratio and i was looking to bump it up to a 3.73 but a question or two is - does anyone have any estimate on how much it would cost in total to get the ring and pinion gears changed out? - and how would it effect its streetability- or 1/4 mile times?

Do some math and make sure the engine is going to be producing power in the RPM range that you will be in with 3.73s or you might find out it goes in the other direction, as I did when I briefly switched my 3.08s with 3.42s.

Also, make sure you have an 8.5" and not an 8.2". The 8.2s were common in your cars timeframe (the 8.5s were not). If the pinion nut is 1.25", you have an 8.5", if it's 1-1/8", you have an 8.2". The rear covers look close to identical.

Pricing - if you have someone do it for you, expect to pay close to $800 or more - consider this when you consider that .05 second you might pick up on the 1/4. You can do it yourself if you have patience and follow the book - proper setup is required if you want it to live quietly - ESPECIALLY with a weak 8.2" axle setup.

Your fuel economy will tank a likewise amount in direct relation to your engines' general RPM increase.

[69NovaKid]

yeah i believe it will be around my power band my trans has a 2,500 stall and with the cam profile i put in 109/107 lobe sep im workin with a higher rpm cam which feeds 3,000 + and i know for sure its 8.5 i had it it built last year and beefed up cause i know id be at the track once in a while

[comp]

it's not enough gear change for the money to me ,,,, i'd spend the $ on more HP, lighten it or a deeper gear,,, i myself love more torque

[69NovaKid]

thats true, what would you suggest for a 355 small block chevy? - ive already got edelbrock performer rpm aluminum heads - air gap intake- lunati cam - headers - 9:5:1 compression -with a dyno simulator (dont know how accurate advertises within 5%) says 425 give or take- anything i can do?

[comp]

Originally Posted by 69NovaKid

thats true, what would you suggest for a 355 small block chevy? - ive already got edelbrock performer rpm aluminum heads - air gap intake- lunati cam - headers - 9:5:1 compression -with a dyno simulator (dont know how accurate advertises within 5%) says 425 give or take- anything i can do?

can you cut the weight down ? is it a track only car ? what carb you using ?

[69NovaKid]

i could - im not sure what to gut - i want to keep it some what looking original - the interior isnt ful - i have bucket seats - no heat - i like the back seat and carpet and all- i woudlnt know what to take out, i replaced the hood with a 4' fiberclass cowl which helped and i just changed the weber 750 cfm to an edelbrock 600 cfm just cuase i wanted to work on something and see if i got any gain out of it and its street/strip ive tried to take it to the strip but its always rained on friday nights or something has stopped me -but id like to make it both if possible