push rod length with new tfs tw's?

94opalgt

Member
May 5, 2005
358
0
17
AKRON,OHIO
as some of you know i just got my heads the other day and i want to make sure i got the right size push rod.im running the stock cam with 1.7 tfs rr's and i bought
6.7 pushrods.is this correct?i hope so cuz the guys that were supposed to help me with this are bailing on me now that i have almost all that i need,and this is my first time doing this.so i'll be searching the forums and asking a ton of ?'s.well thanks for whatever help you guys can give
 
In all likelihood, you'll be looking for a 6.70" or 6.75" length pushrod as long as the heads and block are stock. It's imperative to check using an adjustable pushrod length checker. You can purchase one from Summit for under $20.00 or you can make one yourself.

Don't let anybody guess about pushrod length because if they're wrong, you'll be looking at worn valvetrain components in no time or something more severe depending on how much your length is off. Summit Part #: TFS-9000

Good luck!
 
6.7" should work as should a 6.75". Measure to be sure. Make a solid lifter, then color the valve tip with a black perminant marker and set that rocker. Then rotate the engine by hand 2 times and pull the rocker off and look at the pattern. I think it should be less than .080" and preferably in the middle.

I did not measure when I put the TW heads on my 302, but on my 347 I checked and 6.7" looked fine.
 
ShiftTheDrift said:
In all likelihood, you'll be looking for a 6.70" or 6.75" length pushrod as long as the heads and block are stock. It's imperative to check using an adjustable pushrod length checker. You can purchase one from Summit for under $20.00 or you can make one yourself.

Don't let anybody guess about pushrod length because if they're wrong, you'll be looking at worn valvetrain components in no time or something more severe depending on how much your length is off. Summit Part #: TFS-9000

Good luck!

well im assuming its safe to recommend the 6.700 if thats what comes in their kit? regardless if its been checked or not, i dont see how TrickFLow could sell a kit with improper parts
 
I went with 6.75, because when you buy the heads they come with a big information packet and that is the length it said to buy. But as what was stated before you can always buy a pushrod length checker... or just email Trick Flow
 
igotyofire said:
well im assuming its safe to recommend the 6.700 if thats what comes in their kit? regardless if its been checked or not, i dont see how TrickFLow could sell a kit with improper parts
Well this is very true but TrickFlow indicates to always check pushrod length before ordering for good reason.

IMO, using a pushrod length checker is a general rule of thumb for building or modifying any engine, performance or otherwise.. unless whatever you're doing doesn't warrant changing the pushrods. For example, replacing a head gasket or something benign like that. Of course then, just use the original pushrods. (put back in original positions)

In other words, better to be safe than sorry. :nice:
 
problem is in my case in the future i plan to do a headswap in 1 day, with no other downtime, after checking length if we did do so, i need them ASAP to make this a 1 day job with my friend who is a mechanic. so i cant check them and wait a few days which is why i have concern , i would like to just buy everything i know that works together.....

for EG. why would Engine A be any different from Engine B assuming bottom end and heads were all the same wouldn't they use same length in pushrods?
 
igotyofire said:
for EG. why would Engine A be any different from Engine B assuming bottom end and heads were all the same wouldn't they use same length in pushrods?
In your example, all the internal workings of the SB would be identical, eg. crank, cam and so on. If you know the history behind both blocks meaning differences in deck height are exactly the same, then you would be correct in assuming both SBs will require the same length pushrods. I hope this helps!
 
ShiftTheDrift said:
In your example, all the internal workings of the SB would be identical, eg. crank, cam and so on. If you know the history behind both blocks meaning differences in deck height are exactly the same, then you would be correct in assuming both SBs will require the same length pushrods. I hope this helps!

ok so to clarify since the trickflow kit is designed to work with stock shortblock its safe to assume the pushrod length they throw in will work and its safe to call it a day and not worry about if its too short...., maybe ill just buy those length if i need it and just double check it to be sure when we go to do it, guess thats the smartest thing to do
 
when i bought my heads the big packet that
mustangramair is talking about NEVER gave a specific push rod length,it said to go .5 longer than stock.i thought the stockers were 6.2?thats why i bought 6.7's.but after listening to all you guys i will double check just to be sure.maybe i'll run out to summit and pick up the 6.75's also just to be safe.thanks for all your help guys
 
igotyofire said:
ok so to clarify since the trickflow kit is designed to work with stock shortblock its safe to assume the pushrod length they throw in will work and its safe to call it a day and not worry about if its too short...., maybe ill just buy those length if i need it and just double check it to be sure when we go to do it, guess thats the smartest thing to do
That sounds like a wise decision. You should be okay with doing that.
94opalgt said:
thanks for all your help guys
You're welcome. Good luck!
 
94opalgt said:
when i bought my heads the big packet that
mustangramair is talking about NEVER gave a specific push rod length,it said to go .5 longer than stock.i thought the stockers were 6.2?thats why i bought 6.7's.but after listening to all you guys i will double check just to be sure.maybe i'll run out to summit and pick up the 6.75's also just to be safe.thanks for all your help guys
That's weird, i got the length from the booklet in that packet that gives torque down procedures and how to adjust the rocker arms. Hope everything works out for you :nice:
 
sorry to mustangramair,got home from work reread the packet in the box and it did say 6.75.man i just completely overlooked that.so now i'll go out to summit and pick those up so i have both just in case and return which ever ones i dont use.
 
94opalgt said:
sorry to mustangramair,got home from work reread the packet in the box and it did say 6.75.man i just completely overlooked that.so now i'll go out to summit and pick those up so i have both just in case and return which ever ones i dont use.

If you are gonna have both lengths on hand .................................

I'd paint the top of both valves on one cyl

Put one only together and rotate the motor

Move the checker pr to the other painted valve and repeat the test

Pick the length that shows the best wear pattern and return the others

Later
Grady
 
thats what i am going to do,get both measure and return the ones i dont use.i just dropped the heads off yesterday to get them ported so it will be about a week before i can do anything.thanks for all your help and info