Explain Deck height, please

[STANGALANG]

I'm doing my research and try to find the best 351w block for a stroker set up, capable of handling 500+hp. I'm seeing that the 351w in 69-70 seem to have a different deck hieght than the later engines, what does that mean exactly? Will this change what intake I run or heads?

Also after I buy the right block, what type of machine work should I have done, I know it will have to be bored but what else is required. Thanks for any help you can hand me on this one!

 

[5spd GT]

Deck height is the distance from the crankshaft center (centerline) to the top of the cylinder at the top of the block.

A stock 302 block is 8.2". The aftermarket has 8.7" for the 302.

The 9.2" (Cleveland/Boss), and 9.5" (Windsor) offerings as well, so they are the 351 deck heights.

The 351M/400 engines have a 10.3" deck height.

The taller deck heights allow more room for piston and rod design to accommodates more stroke. The taller deck helps in getting a taller compression hieght piston so you can get all three rings to work as intended, instead of needing any oil ring support rails, aka, the piston wrist pin intersecting the oil ring land.

Basically, a taller deck height allows you to add more stroke (acheived from the crankshaft).

From the factory, the '71-'74 blocks are said to be the best with a true 9.5" deck height and stronger castings. The '69-'70 have a 9.48" deck height. Roughly the same.

The '94 351 blocks are roller blocks.

The "best" block is going to be found in the aftermarket world.

Dart is what I would choose. A 9.5" version at that. It could handle anything you are going to throw at it.

There is a plethara of things that need to be done to a new block.

Torque plate honing, lifter bore honing, machining crank, decking, etc.

It just depends on parts used.

You will be able to run the same heads and intake that are designed for the 351 you choose.

A 302 intake is not going to be wide enough for the taller 351 engines. However, the heads will all bolt-on to each other. Whether 302 or 351 heads.

Good Luck!

 

[jake2582]

if you want 500 reliable hp the right block is AFTERMARKET!

 

[STANGALANG]

Thanks for the great info. I was hoping to not have to buy an aftermarket block, but I would rather spend the money on the front side than later down the road. If you buy an aftermarket block will you still have to spend the money on the machine work or will it already come ready to build?

 

[5spd GT]

You will have to still spend money on the machining, because tolerances can vary so much from part to part.

All engines need to be built independent of one another.

Good Luck!

 

[STANGALANG]

Damn I couldn't buy a break Oh well I want this build to be perfect so I guess that will be my next purchase!!

 

[DocZG]

i would think that a factory block would be fine at 500hp for a 351.... i would get a newer roller block so you dont have to buy the expensive roller conversion lifters.