Final!!! GT40 question ;)

[90foe_5.0]

I finally have the gt40 upper and lower and heads. Now .. I’m going to be keeping by stock H.O cam im only changing heads and up nothing special. I’ve read that I will need to upgrade these springs they are complete remanufactured gt40p heads. What would be the springs I will need to run ? And also Is this somthing that will need to be sent to shop to install ? Heads are completely rebuilt so sucks to change brand new springs but any help is appreciated !
Thanks!

 

[sluggish94]

You'll be fine with those valve springs if you're keeping the stock cam.

Why? Stock cam only has about .444 lift, and even if you upgrade to some 1.7 rockers, it will still only be about .477. Hardly enough to cause any issues. Plus you say the valve springs you currently have are brand new so you should be good.

If you're dead set on swapping valve springs on these heads you have you can use Trick Flow springs PN:TFS-2500100, or Alex's Parts Springs PN:VSK7A49-MOC which match up to your stock cam. Both are "drop-in" kits, meaning there isn't any machining needed on the spring seat. A valve spring swap can be done at home if you have a good spring compressor and some patience. If you're not confident to do it yourself, I can't see a machine shop charging more than like $100 to $150 to swap valve springs.

 

[90foe_5.0]

Thanks for your reply! Yea if there would be no valve float issues with the stock springs I will keep them. I’m not planning on a cam anytime soon im only doing the gt40 swap because I burned a valve apparently on the E7s so I will be pulling them anyways!

 

[Wmac]

Now is the time to upgrade the springs. Overhead valve spring compressor is maybe 20 to 25 $. Watch a youtube video and you will be a pro after the first spring or 2. Very, very easy to do this now, saves having to pull the heads as well as buying new head gaskets.

The TFS kit or Alex's spring kit are both a good choice.