help with gt40 head swap

R

roan65

Member

May 17, 2003

103

0

16

Wasilla Alaska

Feb 16, 2010

#1

• Feb 16, 2010

• #1

I bought a set of brand new gt40 heads (they have been in storage for a few years) and want to replace the factory heads. The gt40s are assembled, and I think all I need to do is blot them on. My questions:

1) Can I use my stock push rods and rockers?
2) is there a bennifit to changing over to roller rocker setup?
3) I am going to buy new head bolts and gasket, is there anything else I need?

 

J

jka

5 Year Member

Jan 17, 2010

339

23

29

Feb 16, 2010

#2

• Feb 16, 2010

• #2

Yes you can use the stock stuff. But if you want to you can swap on some 1.6 pedestal mount roller rocker arms. If you switch to roller rockers they will give you a few horsepower plus reduce wear and tear on your valve stem tips and plus they will keep your valve train more stable at higher rpms. Also if you are looking for good head gaskets plus head bolts go to CJ Pony Parts - Ford Mustang Parts and check out the ford racing head changing kit PART# M6051A50 it's got the gaskets and bolts in the kit plus the valve cover gaskets.

 

Strype

Cuthbert catcher

Founding Member

May 11, 1999

61

34

104

Huntsvegas, AL

Feb 16, 2010

#3

• Feb 16, 2010

• #3

You can use the rockers, but I would make sure and buy new rods. At least make sure they aren't out of round.

 

boosted68stang

New Member

Jan 25, 2009

47

0

0

massachusetts

Feb 16, 2010

#4

• Feb 16, 2010

• #4

your gonna need redusing bushings for the head bolts from 1/2 to 7/16ths I know edelbrock and trickflow sell them and there fairly cheap and id upgrade the hardware to ARP

 

rd

Founding Member

Jan 12, 2000

3,316

63

109

Ocean Springs MS

Feb 16, 2010

#5

• Feb 16, 2010

• #5

Have regular iron GT40's on two engines. Both flat tappet cams. One is using regular production bolt down rockers and stock length pushrods, and runs to 6000 rpm easily.

Confirm that you will need the headbolt reduction washers, probably smog hole plugs for the front accessory holes and in the rear if not using the air tubes. My other set has Comp Cams retro studs and roller tip rockers. They also work fine.

 

cjrpony

Member

Jan 23, 2010

439

0

17

West Michigan

Feb 16, 2010

#6

• Feb 16, 2010

• #6

Your going to need intake gaskets also.

 

R

roan65

Member

May 17, 2003

103

0

16

Wasilla Alaska

Feb 16, 2010

#7

• Feb 16, 2010

• #7

I just ordered ARP bolts and a trick flow stage 1 cam from summit. I think I will run with this for now, and eventually change to 1:6 roller rockers when I figure out what valve covers I want. I have the intake gaskets and head gaskets already, so I should be set! Thanks for the input!

boosted68stang: Are you saying the GT40 bolt holes are larger? So the stock 1/2 bolts need 7/16 bushings to make them work?

 

SpartaPerformance

10 Year Member

Nov 5, 2006

2,517

61

89

Long Island NY

Feb 16, 2010

#8

• Feb 16, 2010

• #8

If you need a general guide on the swap follow this link

Head Swap