well guys this is a little off topic, because its for my 79 2wd c10 not the blazer. but i figure its a chevy truck topic . Its got 4.10's and a 3speed 400 trans, and stock tires. im spinngin my gm crate motor at rps over 3500 rpm to keep upwith slow lane high way traffic. what is a 4 bolt 300hp gm crate motor comfortable spinngin at. i know the max rmp on the slip says 5500 but thats red line. i usuall dont like to cruse at anything over 2500 in the blazer but thats an older motor. what do you guys think. i like the fack the the c10 is fast of the line but theres no top end. and if i were to regear should i go lower than 3.73's to keep the rpms below 3000 at lets say 65 or 70 mph?well thanks guys have a good one.
CK5
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4.10's and a 3speed 400 trans???
- Thread starter 4.030sbc
- Start date
Well , 3.73's will be more cruise friendly but your crate motor can handle the RPM's as long as it is in normal condition. It won't be gas mileage friendly by no means but it won't hurt anything either.
As long as you are O.K. with your fuel consumption; gear it the way you want it and have no fear of killing the motor just because you are turning the motor up a bit with a healthy gear and small tires.
Tom
As long as you are O.K. with your fuel consumption; gear it the way you want it and have no fear of killing the motor just because you are turning the motor up a bit with a healthy gear and small tires.
Tom
ya thats wat i was thinking. i may go to 3.73 just to bring it down a bit, but at least i know i can run it on on the high way a little here and there ,so i dont have to do a gear swap right away. its just a summer ride. thanks for the help
No problem !
Tom
Tom
As already mentioned if the motor is in good shape the 3,500 rpms shouldn't hurt it any.
Regarding gears, dropping down to 3.73's really won't make that dramatic of a difference as it's only around 9% lower (around 300 rpm...you would still be around 3,200 rpm at the same speed).
Regarding gears, dropping down to 3.73's really won't make that dramatic of a difference as it's only around 9% lower (around 300 rpm...you would still be around 3,200 rpm at the same speed).
