GT40/N-41 Cam Setup Help

TorchRed_4.0

Member
Mar 2, 2019
67
2
8
I have GT40 3 bar iron heads with TrickFlow upgraded valve springs:

Kit:

I would like to run the Anderson N-41 Cam with these heads, as well as 1.6 stud mount rocker arms off LMR.

Camshaft:

Do I need the 3/8” or the 7/16” stud?

7/16”:

OR

3/8”:


ALSO: Can I use the stock push rod length, and if not, what length do I need?

Thanks for reading!!!
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
2,896
1,736
133
You will probably have to fool with how the geometry is on where your rocker arms make contact with the valve stem AND the angle on where the pushrod fits into the rocker also........ Get an adjustable pushrod to do this and someway to accurately measure the pushrod length that accomplishes this
 
Last edited:

TOOLOW91

If you're the village idiot what's that make me?
15 Year Member
Nov 29, 1999
7,964
7,994
234
We’re your gt40 heads converted for stud mount rockers ? If not you have pedestal mount rockers .


Given the fact it’s just a cam swap - the heads are staying the same you should be able to get away with your pushrods being the same length . This usually changes when a block is decked , heads are swapped or head gasket thickness is changed . But I would mark the valve stem tip and make sure it has a nice pattern and doesn’t need to be made longer or shorter .
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
2,896
1,736
133
We’re your gt40 heads converted for stud mount rockers ? If not you have pedestal mount rockers .


Given the fact it’s just a cam swap - the heads are staying the same you should be able to get away with your pushrods being the same length . This usually changes when a block is decked , heads are swapped or head gasket thickness is changed . But I would mark the valve stem tip and make sure it has a nice pattern and doesn’t need to be made longer or shorter .
Those roller rockers for a pedestal mount head are pretty cool..... Those are NOT the roller rockers he shows in his post.....
I used these in my "P" heads.. I did not want a true roller rocker for a street car.....
If you use pedestal rockers there is a shim kit you can buy and probably use your stock pushrod length... 6.248?? I think
Roller tip lunati Fulcrum rockers...jpg
DSCF0832.JPG
 

TorchRed_4.0

Member
Mar 2, 2019
67
2
8
We’re your gt40 heads converted for stud mount rockers ? If not you have pedestal mount rockers .


Given the fact it’s just a cam swap - the heads are staying the same you should be able to get away with your pushrods being the same length . This usually changes when a block is decked , heads are swapped or head gasket thickness is changed . But I would mark the valve stem tip and make sure it has a nice pattern and doesn’t need to be made longer or shorter .
The GT40 heads I have are using the factory rockers they came with just upgraded valve springs. I do have a 347 stroker if that matters.
 

TorchRed_4.0

Member
Mar 2, 2019
67
2
8
Those roller rockers for a pedestal mount head are pretty cool..... Those are NOT the roller rockers he shows in his post.....
I used these in my "P" heads.. I did not want a true roller rocker for a street car.....
If you use pedestal rockers there is a shim kit you can buy and probably use your stock pushrod length... 6.248?? I think
Roller tip lunati Fulcrum rockers...jpg
DSCF0832.JPG
I think the GT40 uses pedestal mount from factory, i’m new to all this so excuse my ignorance lol. So Should I use pedestal mount like he put in the link above?
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
2,896
1,736
133
I think the GT40 uses pedestal mount from factory, i’m new to all this so excuse my ignorance lol. So Should I use pedestal mount like he put in the link above?
I am new to this too.... I just went through this building my Explorer engine for my grocery getter mustang a few months ago.....
Just telling you what I did.. These were Lunati roller tip rockers were bolt on for pedestal rocker heads....
My research said that roller TIP rockers will help with valve guide wear... Some say it almost eliminates it.... For the street true roller rockers are a bit of overkill....
Hopefully others will chime in with more experience doing something different with Gt40 and GT40P heads......
 

KRUISR

5 Year Member
Apr 16, 2015
1,364
608
133
I have Crane 1.7 pedestal mount full roller rockers (just like the 93 Cobra did) on both my stock cam and E7 headed engine and my current GT40 3-bar headed and Crower cammed (actually have two full sets of the roller rockers) combo. I used stock push rods with both engine combos with no issues. In both cases I didn't need any shims under the pedestals either.
 

TorchRed_4.0

Member
Mar 2, 2019
67
2
8
I am new to this too.... I just went through this building my Explorer engine for my grocery getter mustang a few months ago.....
Just telling you what I did.. These were Lunati roller tip rockers were bolt on for pedestal rocker heads....
My research said that roller TIP rockers will help with valve guide wear... Some say it almost eliminates it.... For the street true roller rockers are a bit of overkill....
Hopefully others will chime in with more experience doing something different with Gt40 and GT40P heads......
Did those use your stock push rods and did you have to use any shims or anything like that? Also do you have a link to those? Thanks!
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
2,896
1,736
133
Last edited:

TOOLOW91

If you're the village idiot what's that make me?
15 Year Member
Nov 29, 1999
7,964
7,994
234
Those roller rockers for a pedestal mount head are pretty cool..... Those are NOT the roller rockers he shows in his post.....
I used these in my "P" heads.. I did not want a true roller rocker for a street car.....
If you use pedestal rockers there is a shim kit you can buy and probably use your stock pushrod length... 6.248?? I think
Roller tip lunati Fulcrum rockers...jpg
DSCF0832.JPG
I’m aware of what he showed in his post - that’s why I posted what I did because what he posted was wrong if his heads had not been converted which he replied they were not . Nothing wrong with what I sent him .
 
  • Like
Reactions: 1 users