351W 1984 Block will it work? [Archive] - Classic Cougar Forums

: 351W 1984 Block will it work?

March 3rd, 2010, 05:12 PM
E4AE-6018-EA 4

The way I read this casting it is a 1984 351 engine.

My question - Is this block any good for a 427 stroker build up and will all early 69/70 parts be a straight bolt on? i.e. bell housing, fly wheel, power steering, water pump etc

Is the block still thick enough for the 427 stroker build up or should I be looking for a pre 71 block?


March 3rd, 2010, 07:52 PM
That E4AE number is a casting number, denoting they year, model line and engineering group. It does not necessarily mean the block was made in '84 - it could be anything up until '94 when they revised the casting to accommodate the hydraulic roller cam and lifters. The other set of number below the E4AE casting number will provide day, month and year it was cast, i.e. 9F20 would be 1989, F=June, 20=day.

Remember that pre-71 351W blocks have a 9.480 deck height, and later blocks have a 9.502 deck. that .022" difference can make a big difference in some stroker 'kits'.

408- or 418-inch strokers are much more common, since those are just a .030 overbore and a 4.00 or 4.10" stroke.. Save the bigger displacements for a block specifically designed for them like a 4.125" bore Dart block.

Oh, and yes, all of your accessories will bolt up to the later block EXCEPT the newer block probably doesn't have a provision for a clutch Z-bar bracket. I think the 1984 casting revision also included the one-piece rear main seal

March 3rd, 2010, 08:53 PM
So if I understand the higher deck height in later blocks would benefit a stroker? But a Dart or SVO block would be better?

Thanks, BTY was never any good at remembering date code stuff.


March 3rd, 2010, 09:22 PM
"So if I understand the higher deck height in later blocks would benefit a stroker? But a Dart or SVO block would be better?"

Yup, you got it. Higher deck, taller piston(or deeper stroke), better compression.....

March 4th, 2010, 03:10 AM
Dart, World and SVO blocks are made stronger in critical areas to handle the 600+hp power levels that can crack stock blocks in two. They generally have thicker main webs, stronger (sometimes billet steel) maincaps, thicker cylinder walls to handle larger overbores and piston sideloads, revised (larger) cooling jackets... But, they generally cost over two grand for just the bare block!

Some stroker kits will not work in the shorter 9.480" block -- My current 393W for example. You have to add 1/2 of the stroke + rod length + piston compression height (piston above wrist pin) to see how far down the bore the piston top is at TDC. In my case, 1/2 of my 3.85" stroke is 1.925, so 1.925 + 5.956 + 1.608 = 9.489", so the pistons would stick above the block by .009" in an early block, and that's assuming you didn't have to deck the block to square it. Yes, the head gasket compressed thickness is somewhere near .038, so the pistons themselves will not smack into the heads, but then you still have to worry about how close the tops of the pistons will be to the valves when they are still partially open (depends on camshaft timing events). Not a lot of room!!!

Remember, you're going to need some serious-flowing cylinder heads to feed all of those inches! Same goes for camshaft selection! What is 'wild' for a 5.0 is mild for a 16% bigger 351W is downright tame for the 41% bigger displacement 427. You'll probably drop two grand or more for decent cylinder heads, and another grand for cam, lifters, springs, retainers. Add another $300 for new roller rockers. Another $100 for chrome-moly pushrods...

You see where this is going? It can get very expensive, real fast!

So unless you're building an all-out race motor, drop it back a bit and find yourself a nice 10.5:1 408W kit like this (http://www.cnc-motorsports.com/product.asp?ProdID=20794&CtgID=20780), some nice aftermarket heads like these (http://www.cnc-motorsports.com/product.asp?ProdID=26939&CtgID=26809). Add a nice hydraulic roller cam like this (http://www.cnc-motorsports.com/product.asp?ProdID=13684&CtgID=13681) and you'll still have an honest 525hp, 525 lb/ft torque monster that will run on pump gas.