Racing engine are built differently than a street engine. The clearances on the main bearing are larger so the engine spins easier...the clearances on just about everything in a race engine is larger and that's why they are good for street use and we had to run amsoil sae 60 racing oil in that engine and retired it after about 10 races to go with the GM crate program. That bottom end was machined, assembled and balanced by one of the top builders around and I could picked it up for about $1,500 but it would be no good for street use.
One thing that mega picked up on was it's built for higher rpm's and he's right. A race engine is balanced to run smooth at a specific rpm and for a race 350 engine that's around 5800 to 6000 since most tracks don't let you modify the valve train. Normal driving your in the 1500 to 3500 rpm range and you'll definitely feel the vibrations coming from that engine.
One thing that mega picked up on was it's built for higher rpm's and he's right. A race engine is balanced to run smooth at a specific rpm and for a race 350 engine that's around 5800 to 6000 since most tracks don't let you modify the valve train. Normal driving your in the 1500 to 3500 rpm range and you'll definitely feel the vibrations coming from that engine.
