Pushrod sizing for smith bros form - 4.0 V6 OHV

[OX644]

Hi there, Im building a 4.0 with the comp cam 422 and 988 springs

On the forums and the "building the OHV for power" post there is conflicting information about pushrod sizing

The stock Pushrod ballends are closer to 5/16 than 3/16, but why is it recommended to use 3/16? and what would the tube diameter be?

Isn't this the correct size for a engine without milling the head using stock rockers and lifters.

5.550 inch overall length
Straight wall
tube diameter: ???
5/16 ballend and not 3/16

Please correct me if Im wrong, I really just don't have to order twice.

The smithbros form is in attached files

 

[Angie]

hi, if memory is correct here... you can email them directly and ask them giving them all your specs. When i did a 410 cam i emailed them with what i needed and they supplied the information. it was years ago, however they should have a email contact us section. cheers

Contact | Smith Brothers Pushrods

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[gaz]

@OX644 ,

Since you desire the correct length, I recommend using a pushrod measuring kit or simple have them build you adjustable pushrods for a couple dollars more;. This will guarantee the most accurate preload adjustments and afford you the ability to maintain it. Either way, the Smith Brothers can definitely help you with this ..)

 

[Danger ranger 2003]

@OX644 ,

Since you desire the correct length, I recommend using a pushrod measuring kit or simple have them build you adjustable pushrods for a couple dollars more;. This will guarantee the most accurate preload adjustments and afford you the ability to maintain it. Either way, the Smith Brothers can definitely help you with this ..)

I wasn’t aware of the whole preload thing and measuring for the correct length push rods when I rebuilt my 4.0 with the 422 cam. I went with 5.550s. I’ve drove it around the yard and maybe a mile or two down the road since the rebuild and it runs great but I have noisy valvetrain when it gets warm. I’m debating making my own push rod length checker since I can’t find one small enough to measure our lengths and I have a feeling mine will be all over the place. Is there any disadvantages to using the adjustable push rods your talking about?

 

[gaz]

@Danger ranger 2003
Smith Brother's sell those too

 

[Danger ranger 2003]

@Danger ranger 2003
Smith Brother's sell those too

Good to know. I’ll start off by getting a pushrod length checker from them.