What's your RPM?

[Valiant72]

Swapped out my six for a 360 out of a Newport. I'm still using the 7 1/4 until I win the Lottory (at the price for a 8 3/4 I'll need to). Anyway at sixty I'm turning 3 grand. Is that about right? Have a 904 and I'm guessing a high ratio third member. I'm so use to the overdrive's it sounds high.

 

[Mrmopartech]

What is the rear end gear ratio and the tire diameter.Lets assume the tach is reading correct,and that it is not still in there from having the /6.If it is,you need to open the tach and switch the switch to 8 cylinders from the six.Or if its a new tach make sure its on a 8 cylinder setting,or 4 cylinder setting.get the info and post it and I will do the math for you.Also what speedo gear are you using in the tranny,if its not the right tooth gear,its going to give the wrong speed,Mrmopartech

 

[Valiant72]

Thanks Mrmopartech. I completely forgot about changing the tach setting. I'll have to do some basic checking for the gear ratio. I know the speedometer is off but I've never tried changing a gear. Maybe I can work on it tomorrow. Thanks again.

 

[OldVart]

As Mrmopartech said, re-set the tach, measure your rear tires for installed height, and post the numbers. You might also check on the rear end itself to see if there's a gear ratio tag still attached to one of the cover bolts. That's a very nicely done engine bay you have there. Also, I ran a 7.25" rear end for about 15 years in my Vart behind a well warmed over 360 and it's still in great shape, although she gets a 8.75" this time. The biggest things to keeping the 7.25" alive (1) absolutely NO brake stands. If your foot is on the brake, don't touch the gas pedal. That's how my first one expired behind a hot 318. (2) Don't punch it going around corners cause they'll spit those little side gear teeth right out of there. Good luck.