454 455 hp sm465 410 gears

[NOPHO84K30]

Im looking to buy a new motor, mines old worn out .i have a sm465 trans 205 t case
14bolt ff 410 gears 35 inch bfg km2s. This motor is pro built at a shop in phx 455hp 5200rpm... Just want some opinions on how this things going to drive. Right now im at 3000 rpm 70mph on the freeway. Is that too much rpm am i going to start breaking everything else. Need to regear axles? motors 5200$ ready to go

 

[woodsrider250]

That motor likely has a power curve shifted higher than what most would build for a truck. That being said I'd say you're going to be geared fine for it....as opposed to cruising at 2k where this motor is likely not making much power yet. Would want a looser converter I'd think, but the cam will dictate that.

 

[NOPHO84K30]

Its a three speed with granny. you think it can turn at those rpms and not have issues or would i be limited by the trans and x case there both all gear

 

[Jims86]

That shop should be able to build a good torquey truck engine....its really stupid to have to cruise at such high rpms in a truck, unless its a trailer queen, and intended only for drag racing.

 

[woodsrider250]

Got nuthin to do w/ the motor....as you know. 90% of these 3/4-1T's come with 4.10's...as you know. So what's better....Build a motor specifically designed to cruise at 3k RPM which is where it's going to run without regearing, or build a motor designed to cruise at 1800, and turn it 3k? For mine I bought a 3.73 rear as I consider a 3k@70 cruise unacceptable, and band-aid for the 140hp stock motor. However, that would be perfect for a 'racier' engine. Still undecided on a BBC or 383....Either of which would be built to be a little over peak TQ at cruise regardless

 

[hirschdalechevy]

The gear chart shows 2,762 at 70 mph with 4.10 gear's and 35's , which is not that bad . You could run a gearvendor's overdrive and you would have a sweet set up , but they are spendy. You could also try and stay at 65 mph most of the time and be at 2,564 rpm , which is a little better , or slap some 37's on your ride to soak up some gear.