? about valve springs for GT40 heads

Pirate209 · 06-21-2002, 09:50 AM

I recently picked up a set of GT40 heads off of a 96 explorer. They are the regular GT40s not the Ps. I planned to home port them and upgrade the valve springs. I bought the ones that Crane Cams website recommends part #99841 and the locks and retainers. I have read since then that there is some weird locks or something on the stock valve springs and it requires special valves, locks, or something. If anyone could shed some light on this and tell me if what I have bought will work would be greatly appreciated.

Old Guy with 87 GT · 06-21-2002, 10:51 AM

the *stock retainers are different and won't work with the crane springs .........i recently purchased the same springs ,but i got the crane kit that comes with the retainers and locks(part #44308-1) ............the stock retainers are conacal and are different for the intake and the exaust valves (the spring heights are different and there a different design )

if you got the retainers that crane recommends for the springs then they should be fine ......they designed there parts to work with the stock valves .............but .....although the locks arent that much different from the stock ones ,they effect the springs installed hieght ......you have to install them and then check the spring hieght .......they should be within specs ,if not then you'll have to shim springs or get different locks

on mine i had to shime the intakes like .030 to get the instaled height ,then on the exaust valves the spring hieght was to high and the locks in the kit didn't work with my roller rockers (the rocker would have hit the retainer ),so i had to get different locks that lowered the springs hieght .050 .....on the exaust valves with the different locks my spring height was good without any shims

been running the set for about a month with no problems

Pirate209 · 06-21-2002, 11:08 AM

Thanks, that is more detail on what I have heard. What locks did you get for the exhaust valves. That is all I need because I have the retainers and locks like in the kit already.

Old Guy with 87 GT · 06-22-2002, 09:56 AM

the locks i had to get were part #99096-1

according to the tech guy at crane ,the different locks are rarely needed ,.... but there are variences in tolarances on every moter and on mine i needed the locks to use the springs with my roller rockers

it might be a good idea to get some washer shims to have on hand before installation (there pretty cheap ) but i'd wait to get different locks intill you see if you need em (there like 30$ for the set )

crane sent me the lock kit for free since the origanal kit i got was suposed to work with my crane rockers ,and stock heads .......i got goofy tolerances on my heads , so the kit didn't work .......(.the guy at crane was pretty cool ,went out of his way to get me the locks quickly ) anyway ....i don't think there needed vary often

well hope i helped .....good luck

06-21-2002, 09:50 AM	#1
Pirate209 Registered Member Join Date: Jun 1999 Location: Greenville, NC, USA Posts: 34	? about valve springs for GT40 heads I recently picked up a set of GT40 heads off of a 96 explorer. They are the regular GT40s not the Ps. I planned to home port them and upgrade the valve springs. I bought the ones that Crane Cams website recommends part #99841 and the locks and retainers. I have read since then that there is some weird locks or something on the stock valve springs and it requires special valves, locks, or something. If anyone could shed some light on this and tell me if what I have bought will work would be greatly appreciated.

06-21-2002, 10:51 AM	#2
Old Guy with 87 GT Registered Member Join Date: May 2001 Location: Harrisburg, Pennsylvania Posts: 379	the *stock retainers are different and won't work with the crane springs .........i recently purchased the same springs ,but i got the crane kit that comes with the retainers and locks(part #44308-1) ............the stock retainers are conacal and are different for the intake and the exaust valves (the spring heights are different and there a different design ) if you got the retainers that crane recommends for the springs then they should be fine ......they designed there parts to work with the stock valves .............but .....although the locks arent that much different from the stock ones ,they effect the springs installed hieght ......you have to install them and then check the spring hieght .......they should be within specs ,if not then you'll have to shim springs or get different locks on mine i had to shime the intakes like .030 to get the instaled height ,then on the exaust valves the spring hieght was to high and the locks in the kit didn't work with my roller rockers (the rocker would have hit the retainer ),so i had to get different locks that lowered the springs hieght .050 .....on the exaust valves with the different locks my spring height was good without any shims been running the set for about a month with no problems __________________ the "not so old",old guy 87 Mustang GT T-top >hanlon t-5, pro 5.0, centerforce clutch ,adj. cable/quatrant ,3.27s ,full 2 1/2 ex(off road H) adj. reg. ,e-cam ,70mm TB, cobra intake ,1.7rr ,ported/milled e7ets w/crane springs ,306 balaced/decked short block w/speed pro forged flat top pistons ...257rwhp/302rwt best et 13.7@102 (4/11 ) '80 Capri (future project,currently collecting parts for 351 moter)

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06-21-2002, 11:08 AM	#3
Pirate209 Registered Member Join Date: Jun 1999 Location: Greenville, NC, USA Posts: 34	Thanks, that is more detail on what I have heard. What locks did you get for the exhaust valves. That is all I need because I have the retainers and locks like in the kit already.

06-22-2002, 09:56 AM	#4
Old Guy with 87 GT Registered Member Join Date: May 2001 Location: Harrisburg, Pennsylvania Posts: 379	the locks i had to get were part #99096-1 according to the tech guy at crane ,the different locks are rarely needed ,.... but there are variences in tolarances on every moter and on mine i needed the locks to use the springs with my roller rockers it might be a good idea to get some washer shims to have on hand before installation (there pretty cheap ) but i'd wait to get different locks intill you see if you need em (there like 30$ for the set ) crane sent me the lock kit for free since the origanal kit i got was suposed to work with my crane rockers ,and stock heads .......i got goofy tolerances on my heads , so the kit didn't work .......(.the guy at crane was pretty cool ,went out of his way to get me the locks quickly ) anyway ....i don't think there needed vary often well hope i helped .....good luck __________________ the "not so old",old guy 87 Mustang GT T-top >hanlon t-5, pro 5.0, centerforce clutch ,adj. cable/quatrant ,3.27s ,full 2 1/2 ex(off road H) adj. reg. ,e-cam ,70mm TB, cobra intake ,1.7rr ,ported/milled e7ets w/crane springs ,306 balaced/decked short block w/speed pro forged flat top pistons ...257rwhp/302rwt best et 13.7@102 (4/11 ) '80 Capri (future project,currently collecting parts for 351 moter)