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Discussion Starter · #1 ·
I have 68' J code 302. It's been rebuilt... 20k miles on it so far. I just recieved some 69' 351w heads. Yes I'm doin' 331 stroker.

Question: Can I use any of the hardware from my 302 heads on the 351 heads. More specifically the rockers? The 351 heads have new hardware on them except the rockers.

I have everything else I'll be using:
331 stroker crankshaft
65' 289 connecting rods
Performer RPM E.B. intake
750+ cfm carb (I have a couple avail. to me gonna try
them all and see which one I like the best)
69' 351w heads
all new ignition components
new headers/exhaust/cold air intake
282s Flat tap cam
and some other extras and a little machining where it counts.
 

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What rockers are on the 302 heads? I'll guess we're talking stud mount rockers in both case.....so yeah, they should transfer over fine.

Do the 351W heads have screw in studs? Guideplates? Or are they pretty much a stock W head?

Just curious, but you didn't list the pistons.
 

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If the heads have the stock rockers and studs I wouldn't use them with the cam you mentioned. The stock set up on both the 302 and 351 heads uses pressed in studs and non-adjustable rockers. A performance cam should be matched with adjustable rockers to properly set lifter preload (or valve lash if using solid lifters), and the pressed in studs have a shoulder which makes adjusting the rockers impossible. Pressed in studs (even the adjustable type without the shoulder) are kind of iffy when spring pressure and valve lifts are increased over the stock cam anyway. Screw in studs are much more reliable for a performance application.
 

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Discussion Starter · #4 ·
well the pistons are an undecided area. I was going to obtain some Kieth Black 322. but the pistons that are already in the block are in excelent shape. Even the rings look good. I'll change them anyways because I'll full access and the pistons will be out. But I unfortunatley have no other info on the ones in the block right now other than that they are some brand of otherwise performance pistons. I wasn't involved in decided all the items that were put on the block at the time of rebuild. Thanks guys. Anything/anyone else?
 

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The stock set up on both the 302 and 351 heads uses pressed in studs and non-adjustable rockers.
The stock 351w heads used non-adjustable, positive stop rockers. The 302, however, used fully adjustable rockers until '70. Since his J code heads are '68's, they'd be fully adjustable rail rockers, unless they've been modified.
 

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You can't use your current pistons. 331 strokers require different pistons. (different compression height IIRC) You can use a few different rod lengths with the 3.25" crank IIRC, and rod length is VITAL to piston selection. You've gotta know the length of the rods you'll be using before you can pick out pistons with the correct compression height. Compression height how far from the top of the piston the pin is located.
HTH
--Kyle (I just realized I actually know what compression height is! Dang!)
EDIT: IIRC the KB322 is the piston blkfrd used in his 331 stroker with 289 rods.
 

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I would not swap J code heads for 351w heads. The huge loss in compression would not offset the gain in valve size. You'll loose almost a full point (.8 to be exact) in compression.

The only reason I would do this, is if the pistons you choose are matched to the 60.4cc combustion chamber of the 351w heads, intstead of the 53.5cc of the 302 J code head.
 

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well the pistons are an undecided area. I was going to obtain some Kieth Black 322. but the pistons that are already in the block are in excelent shape.....
Doesn't matter if they're brand new in the box..too tall of a piston for your stroker applicaton.

The piston you mentioned has the right compression height (1.405) to use with the 3.25 stroke crank with 289 rods.
 

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Discussion Starter · #9 ·
thank you all. Looks like I will continue on obtaining ALL the right parts (i.e. the pistons) rather than trying to save a buck. KB322's on the way. As well as new rockers. Thanks again.
 

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You should read this if you haven't already. I wrote down my experiences a few years ago (with occasional updates) to help others as much as I could who were interested in a 331 with 5.155" length rods (289 length). Best of luck (and skill) and let me know how it runs.

lessons learned
 

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id get the W heads and have them redone with new hardened seats and stainless valves along with screw in studs and roller rockers....

At least port the exh side and you'll be good to go
 

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Discussion Starter · #12 ·
Everything on the heads that you've mentioned are done except the rockers. Porting is taking place in early January. Gonna do it right the first time... well at least try to.
 
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