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Discussion Starter · #1 ·
I have a set of GT40 heads off of a '94 Cobra waiting to go on my mildly built '68 302. Stock valves (1.84/1.54) and valve springs, and I'm waiting for my Crane 1.7 rollers to come in the mail (stock replacement; the guy I bought the heads from kept those).

My questions are:
1) Will I be able to use my stock pushrods? I'm currently using a Crane 130052 (Energy 272) cam w/ hydraulic-flat lifters.

2) What's the best way to measure valve-piston clearance? I replaced the pistons previously, but I'm not sure what I have in there right now


3) The intake port on these heads seems smaller (comparing gaskets)... I currently have an Edelbrock Performer manifold and no money to spend on something new; should I gasket-match the intake port on the head or epoxy the manifold port down?

Thanks for any help! I did some searches, it seems like you guys really know your stuff!
 

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You need to get the pushrods intended for a 1977 - 1985 302 with bolt-down rockers, and flat tappet lifters.

I'll let better qualified people answer the other questions.



cheers
Ed N.

_________________
95 T-Bird SC 3.8 V6 5-speed, 1 of 574
68 Cougar 289 EFI restomod
87 Lincoln Mark VII LSC 5.0 HO -- SOLD

<font size=-1>[ This Message was edited by: fastEd on 2/22/06 7:15am ]</font>
 

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Discussion Starter · #3 ·
So, looking at a couple of parts house web sites, it looks like my '68 stock length is somewhere around 6.81" and 1980 2v 302 non-roller w/ pedestal bolt-down heads (I used F-150) is around 6.880".

Is this "close enough"? I guess it's close enough to at least assemble one cylinder and check rocker tip travel on the valve?

Or, where can I get one of those adjustable-length pushrods to figure out the perfect length?

Also, what is the <b>proper</b> procedure for setting valve lash (for lack of better word) on hydraulic lifters? I was recently informed that "tighten until snug, then rotate 1/2 turn" is incorrect, even though that's what my cam install instructions said...
 

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Discussion Starter · #5 ·
Yeah, that's gonna be the best...
Anyone know where to get one other than online order? (I'd like to hold it in my hand before I buy it...)
 

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Discussion Starter · #7 ·
Thanks for all the info, guys!

New question, same combo:
Head gasket? Should I use a '94 Cobra head gasket (i.e. match the head) or a '68 302 gasket (i.e. match the block)? This is not high compression (9.5 or 9.0 I think), hoping to spin to 5,500 maybe (is that optimistic?)... and where can I get those plugs/inserts to use my existing accessories (alt/ps) and plug the EGR ports?

Thanks, you guys rock!
 

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I would thing the 94 head gaskets would be fine, the 9:1 is about right and 5500 should not be an issue. Check at you local machine shop or auto parts store for plugs. Hang loose !!
 

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1) not unless you cut the heads for screw in studs.
2) assembled: set the engine to the intake centerline, put a dial indicator on the intake valve and compress with a fabricated lever. Note reading when valve contacts piston. Other - install clay on piston top, install head w/o gasket, use two solid lifters, cycle engine. Cut clay and measure clearance. On a stock motor up to about .512 lift you should not have ny problems.
3) heads flow better than the old stockers, I wouldn't waste my time porting to a Performer intake.
4) head gasket - use the stock 68 gasket (FepPro 1011-1 IIRC) and drill the four missing steam holes in the head to match the block - use the gasket as a template.
5) plug the EGR passage using 1/2" rod from the home store and some threaded plugs. The inserts are available from a local auto machine shop.

_________________

1967 Falcon 4 door w/351C - Owner built, owner abused.
70 Mustang 302 / 02 Mustang V6 rag top, 04 SuperCrew parts hauler
http://raceabilene.com/kelly/hotrod

<font size=-1>[ This Message was edited by: ckelly on 2/28/06 11:29pm ]</font>
 

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Discussion Starter · #12 ·
Thanks for the info.... I guess I'm not as happy anymore.


On 2006-02-28 08:29, ckelly wrote:
1) not unless you cut the heads for screw in studs.
At some of the online parts houses, the pushrods for "1980 F150 302" (which should be a flat-tappet, bolt-down-rocker engine, right?) are same length as the ones listed for my '68 302? Is this not correct?

2) assembled: set the engine to the intake centerline, put a dial indicator on the intake valve and compress with a fabricated lever. Note reading when valve contacts piston. Other - install clay on piston top, install head w/o gasket, use two solid lifters, cycle engine. Cut clay and measure clearance. On a stock motor up to about .512 lift you should not have ny problems.
This is the method I was going to use, but I didn't think of setting it at intake lobe centerline (duh). With 1.7 rockers I'll be at about .515", but I'm not sure if my pistons are taller or shorter than stock (or same size reliefs, or ?). Dad's looking for the info from when we bought the pistons back in '97.

3) heads flow better than the old stockers, I wouldn't waste my time porting to a Performer intake.
Yeah, these heads will flow a LOT better... but won't I do even better to get rid of that big step? Or is it not a big deal?

4) head gasket - use the stock 68 gasket (FepPro 1011-1 IIRC) and drill the four missing steam holes in the head to match the block - use the gasket as a template.
That is, on the head/block mating surface? Icky...
FRPP lists one engine gasket set (6003-A50) for 289/302/351W '63-'01? Does this have steam passage holes that are simply not used if you have a later block/head?


5) plug the EGR passage using 1/2" rod from the home store and some threaded plugs. The inserts are available from a local auto machine shop.
Sorry, I don't understand this; should I get 1/2" rod or should I get threaded plugs? Or just some bolts with thread locker?
 

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Clarification:
Do some searching here on FM - you should find a lot of posts relating to the steam holes. I drilled 4 in each head. I believe if you don't and you run the GT40s on an early block, you will have overheating issues. Just line up the gasket, center punch, drill and suck out the fuzz with a shop vac - not a big deal.

On ours, I filled the EGR passages with steel rod and capped the ends with a small space filled with high temp silicone and threaded hex plugs. On the left side head, I used less rod and threaded in the reducer to accept the alternator mount. Your option, fill or just cap. I think the hex plugs look cleaner but you can stick whatever in there to close them off.

On the pushrods - I never checked, I had the heads cut for screw-in studs so we could transfer the existing valve train pieces over. The stock 302 pushrods that were in the motor are still in the motor and the geometry is close enough for this engine. If you're not cutting, get an adjustable pushrod and measure - you SHOULD be able to use anything from a 302 type engine that used the GT-40s because the deck is the same - IF the cam was a similar flat tappet.
 

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Discussion Starter · #14 ·
Thanks for the clarifications!

On the rocker/pushrod issue, I know that the rocker set comes with shims to raise the rockers up to 0.090" (16 0.030 and 16 0.060 shims) off the head; I need to find out how to properly set the lifter preload, I guess?
 

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Discussion Starter · #16 ·
Yup, got the rockers yesterday and there are good instructions in the box.
Early next week I'll get my head gasket set and do the swap; hopefully the pushrods are the right length, hopefully 1.7 is not too much!
 
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