Pushrod Length for 351W with GT40s

[Jambi]

I'm in the process of rebuilding a 351W that came out of a '95 F150, and I'm putting GT40 heads from a '96 Explorer on it. I recently ordered a roller rocker/pushrod kit from Summit but the pushrods are too short. I no longer have the heads or valvetrain from the 351 to use as a reference point. I've put '95 F150 and 5.8L engine in at the Summit, Jegs and Rock Auto sites to try and get an idea of the length of pushrod I would need, but several different lengths are shown. Or, if anyone has a rocker arm/pushrod recommendation for this engine/head combo, I'd be interested to hear it.

 

[blubuckaroo]

It's always best to measure with an adjustable push rod, then buy the correct ones.
Nobody can make an accurate recommendation for push rod length. There are just too many variables.

 

[jckkys]

I just went through the same scenario with my 351 with '96 Explorer GT40 heads. I got the hydraulic roller cam and kit from Comp Cams and it worked but it's assembled so the push rods are unavailable to measure, but I'm sure Comp Cams has the info. I would like to point out that because the heads are drilled and threaded for 5/16" base studs, guide plates aren't made for this. If I knew while the heads off, I would have drilled and threaded them for 7/16" base studs, so guide plates would be easy to find.

 

[jckkys]

I want to add that I did the guide plates and studs to use adjustable roller tip rocker arms.

 

[EricLar80]

Measure and buy the right ones.

 

[Broncobowsher]

Measure is the only way. Even stock there were + and - pushrods. Now mix in re-machined parts, and aftermarket parts. There is no way to just tell you what you need. You didn't list everything. The cam you are running may have a slightly smaller base circle, which alone isn't a big deal. and your head gasket may be a little thicker, which alone isn't a big deal. Put them together and now you are off by a size. A pushrod checking tool is the only way to know what will fit your engine.

 

[Timmy390]

Bought mine form this guy
https://www.alexsparts.com/categories/PUSHROD-LENGTH-CHECKER-TOOLS/

As said measuring is the only way to do it "right"

For me, stock 96 351W pushrods worked on my 96 block with GT40P heads non adjustable rockers.

Tim

 

[rjrobin2002]

I was planning to use my stock 1995 f150 351 push rods with my explorer gt 40 and rocker arms.

That wont work?

 

[fordguy]

Measure is the only way. Even stock there were + and - pushrods. Now mix in re-machined parts, and aftermarket parts. There is no way to just tell you what you need. You didn't list everything. The cam you are running may have a slightly smaller base circle, which alone isn't a big deal. and your head gasket may be a little thicker, which alone isn't a big deal. Put them together and now you are off by a size. A pushrod checking tool is the only way to know what will fit your engine.

Good advise, I went with comp cam’s recommendation and it was wrong

 

[Timmy390]

Good advise, I went with comp cam’s recommendation and it was wrong

I did the same thing with my FE build.....Crane was WRONG.....turned in to a mess

Tim

 

[73azbronco]

Anything other than stock vs stock parts, you need to measure that dimension sorry. And may need to buy more than one size pushrod checker.

 

[KyleQ]

Stock stuff works, been running stock pushrods on a 351w with GT40's for years.... send it!

 

[Jambi]

I actually was not aware a pushrod measuring tool existed until now, so I've gone ahead and ordered one.

 

[jckkys]

If you did what I suggested, the valve would be adjustable and exact measurements or custom length push rods would be unnecessary.

 

[EricLar80]

If you did what I suggested, the valve would be adjustable and exact measurements or custom length push rods would be unnecessary.

Even the ones that have to be adjusted only work with a certain range of pushrod length. Machining your heads and buying aftermarket parts are both good reasons to measure. That, orbit the stock ones and see if they fit, and re-buy if needed.

 

[Broncobowsher]

I've done one and used the checker. Ended up with stock length pushrods. But you have to know which version of stock pushrods because they come in a lot of different lengths. When I say stock length, I used flat tappet length pushrods on roller lifters. But I would never have figured that out without using the checker tool.

 

[nvrstuk]

Just because you can sometimes make the valve lash adjustment "work" by not measuring for the correct length pushrod doesn't mean it's right OR will last any amount of time. There is a definite pattern you want on the valve tip and that is why you measure for the correct length pushrod so that wear pattern will be perfect meaning the rocker is pushing down as straight as possible with as little side load as possible. Lots of variables but in a nutshell...dont' cheap out. Get the tool and use it.

Sounds like you're on the right track

 

[blubuckaroo]

Just because you can sometimes make the valve lash adjustment "work" by not measuring for the correct length pushrod doesn't mean it's right OR will last any amount of time. There is a definite pattern you want on the valve tip and that is why you measure for the correct length pushrod so that wear pattern will be perfect meaning the rocker is pushing down as straight as possible with as little side load as possible. Lots of variables but in a nutshell...dont' cheap out. Get the tool and use it.

This is just one of the steps that amateur builders often miss.
Another is measuring the valve spring height and pressure so the springs can be shimmed for correct pressure. If you're changing components, there are too many variables to just order from a catalog.

 

[RG75Bronco]

I am in the same situation with my engine assembled and installed. I have GT40p heads on a 302 and I believe I can get a pushrod measuring tool seated in the lifter. If so couldn't a measurement be taken??

 

[blubuckaroo]

Sure. I've done pushrod measurements when swapping cams.