ralfmotorsp\orts

If i was to buy the new gm ls3 block for my 416 build, do they come fully machined and decked? or would it still need to goto the shop?

litle88

iTrader: (20)

Back to the shop and also clearanced for the stroke.

Gordon0652

iTrader: (4)

To the shop!

67SS509

iTrader: (25)

Does not have to be clearanced for a 4" stroke to make 416 cubes. If you buy your piston with the right compression height it will not need to be decked. Bore will be finished to size for piston. 4.065", just let a shop double check it for you.

Gray86hatch

iTrader: (83)

My 4" with eagle rods needed a notch.

Send it to have it looked over cleaned cam bearings installed.

Tim

litle88

iTrader: (20)

Same here with eagle hbeams.

To the shop ( that deals with ls motors) sir, do it once and do it right or you'll be paying twice. Take it from guys that have been there and done that lol.

Che70velle

iTrader: (6)

The ls3 blocks come with cam bearings installed. I'd take it to a builder to check it. Very cheap insurance.

01 blue ss

iTrader: (2)

No notch needed with my Callies rods.

allblowdup

They come complete ready to assemble. There even pretty clean out of the box. I would clean it again anyhow. Only problem for your 416 is that they are just straight bored for the 4.065 factory piston at .00005 clearence and deck plates are not used when they are honed. No prob for the factory as they are designed to wear but with a 416 and forged pistons it should be rehoned with deck plates and get your proper clearence. They move a ton with the deck plates.

67SS509

iTrader: (25)

You have a few too many 0's there for the factory spec.LOL The block bore stays the same whether it's a factory cast piston or a forged piston. Clearance is designed in the piston sizing. Typically a forged piston would be .003" to .005" smaller than the 4.065" bore. The factory cast piston would be .00075" to .0015" smaller than the 4.065" bore.

fd3sls2

iTrader: (3)

I would definately recommend going to 4.070 (using a deck plate). Also worth noting....check piston to deck height in cylinders (1,2,7,8)... GM didnt do a very good job at holding parallism (at least with my brand new ls3 block)... mine was .004 differance from front to rear....and .002 different from one side to the other.....

fd3sls2

iTrader: (3)

I built one engine for my friend with eagle rods (needed clearancing)... but my compstar 416 setup didnt need clearancing...fwiw. (both 4" strokes