Thread: 400 crank/305 block

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Has anyone actually built one of these that could comment? I already have the 305 in a vehicle that I don't use,so money wise,and horsepower wise it would be good for what I want to do. I do plan on a 383 in a couple years but for now I want to use the 305 block. This is a mild brackett racer that I am just starting so after building this and getting the suspension,traction,and bugs worked out I'll go 383.
Probably will buy a Scat rotating assembly.Will this need balanced by an engine builder? And I am assuming that it will transplant into a 350 block with just a piston change,when the time comes to go 383??? Anyone do the 400 crank,rods,balancer,flexplate,??? in a 305? And I am assuming that you don't just buy a 400 crank,rods, balancer,flexplate,put it together without a machine shop balance act? Doesn't anybody on this site root for the underdog or try 'different' builds?

Any suggestions?anyone here done this? And,,,it will be temporary,vehicle is just starting and the rotating assembly will be used for a 383 in a couple of years.I have a 305 in a vehicle that I don't use so I thought I would build this,,,get suspension,traction,bugs worked out and then in a couple years go 383. Will probably order a Scat rotating assembly. Will I need to have the 400 crank,rods,balancer,flexplate balanced by a machine shop? Any other suggestions???

Well, it will work but they are going to have to cut a lot of meat out of the counterweights on the crank in order to get it all to balance because of the 305's tiny pistons. This means when you do put bigger pistons on there, you're going to have to have to use mallory in the crank to bring back the weight. Good luck finding pistons with the correct compression height for that crank. You may be able to do something with 400 rods and 305 pistons. Finally, you're compression ratio is going to be mighty high. You may want to use 350 heads on the 305 to bring it down some.

What 76GMC says is right...that's why a 305 crank is different from a 350 crank even though they both have a 3.48 inch stroke.

Why spend more money to build a 305 stroker than it would cost to build a 350 stroker? Engines (and other endeavors) benefit from longer strokes.

Originally Posted by robot

Engines (and other endeavors) benefit from longer strokes.

aw but ive seen articles that indicate a trend shifting towards smaller strokes <and journal sizes> well thats what hot rod & car craft said

i dont do chevys myself i'm a ford guy.... but i can tell ya that you'll want to get it balanced even if it does say balanced assembly..... just to make sure, along with a clearance check...... cause even if it seems to clear when you hand turn it doesn't mean it will at say 5500 rpms...... shouldn't cost ya more than $100-$150 to have done.... last time i had a balance done it was by an expensive shop and they charged me $80

It cost me something like $150 for a balance. They went all out, too. They even balanced the rods by grinding down the big ends a little. They balanced the flexplate and torsional damper while they were at it.

SNH,
Go ahead and build the 305/335. The biggest problem you will have is heads. Don't use the 305 heads use good aftermarket (World Products makes nice 305 heads) heads and build it like any other sb chevy. You will have a "square" (3.75" x 3.75") motor and should have a lot of torque. I am going tp build one sometimes in the future with a TPI. This a link to Powerhouse who builds a kit for this application. I don't think I would try to put together an assembly myself because, as has been pointed out, it would be cost prohibitive.
Just my thoughts and good luck.
Jim
Also, I think you would only have to change pistons and rebalance to build a 383.

http://www.enginekits.com/ek/RetailCatalog.pdf#search='powerhouse%20335%20stroker'