Hey guys, usually hang out in the 7.3 diesel section. I just put up a garage and started on my first project. I have never rebuild an engine but decided to start this for a winter project. Motor is actually out of a 65' thunderbird but it is a big block 390. I want to keep this as absolute stock as possible.

So far I took the heads off and sent them to a machine shop to get them cleaned up in a hot wash tank. I ordered new springs to replace the old ones since the motor had about 97k on it and they were more then likely worn out.

I ordered new springs but like i mentioned this is my first time rebuilding an engine. The newer springs are slightly taller...does this matter? I know it will probably put more pressure on the valve seat. I am trying to find the original uninstalled height of the factory ones but i cant find it anywhere online.

I put up a picture here to help show what i am talking about.

 

Looks normal, the old ones will have taken a "set" and aren't as strong anymore.

If you're cutting the seats, or the face of the valves, you'll gain some compressed height anyway, which is usually why machine shops shim the valve springs after a head rebuild.

 

No adjustments made by the machine shop just the hot wash and then I was going to throw everything back together I'm trying to keep it in stock as possible that's why I was worried about the different height. I attached a picture of one of the heads that has yet to be sent out yet showing the valve seat

 

I would strongly advise getting hardened valve seats installed for todays gasoline. Now's the time to do it. Valve guides would also be in order at 97,000 miles if you don't want a stop light smoker.

 

FE engines installed valve spring height is 1.82", +/- 0.005"....in a perfect world. 1.80" - 1.85" would work. Put a straight edge across the valve tips to check height when you get them back.

What cam are you going to run....close to stock?

 

Great winter project, I started mine 2 yrs ago, now I am working in a garage as this new house in KY doesn't have a shop.....Have fun.

 

As 69cj explained and I as will have a set of FE older heads that needs to go to the shop and have the hardened ( Carbide seats installed) ??/ As all seats on FE heads are induction hardened That means they used the material in the head to anneal ??/ Most of the time these heads are fine if they have never been ground ( Milled Material that was removed under the valve , The spring seat ) The hotter temperatures of the unleaded fuels will eventually pound the seats out ??/ Also what were these springs sold as ??/ Stock replacement , High performance or what ??/ Did you get a spec. sheet with them ??/ The increased high will add cam response ( A good thing ) except more pressure on the valve seats ( Not a good thing with stock valve seats ) also check for coil bind ( distance between coils when collapses ) ??/ If the the springs are longer ?? There's going to be less measurable distance between the coils ( A bad thing if not enough tolerance )??/ Something else you might think of is my engine had a load ticking and running rough ??/ Pulled a valve cover and it had a rocker arm falling off the top of the valve tip falling onto the spring retainer??/ My solution was a after market set of alum. spacers that take the place of the spring ( Weak link )dividers between the rocker arms ??/

 

This normal?

 

Guides replaced one head , rings inside the other guides, valves appear to have very little wiggle ,carbon in the lifter valley pan passenger side.