valve spring swap -- need help

[Old Guy with 87 GT]

i'm planning on swapping my valve springs tommorow ......i'm going to do it with the heads on the car(friend of mine has tools ,using air )....i'm replacing stock springs with crane kit 44-308-1

well i'm planning on having a friend help me thats a little bit more knowlegable then me......but this is new territory for me ,i've never done this myself and i want to make sure i do it right ......i'm not a total novice but i still have alot to learn

what do i need to know before i start this job .......i was told i will have to check spring height and pressure ....i might have to use washers to shime spring height .....not sure the proper way to do this so any help or advice would be greatly appriciated

if there's any other thing i should know ....please tell me i don't want to do this again

details>its on the 87gt ,i'm using stock valves on milled 7ete heads(.02) with 1.7 rollers ...it was recommende to use the crane kit i got ,(44-308-1)should have sufficient pressure....the heads were just reconditioned with all the clearances checked and i'm going to pessurize the cylinders to hold the valves in place

thanks in advance for any replys

[Jeff Chambers]

Depends on a lot of factors. If your heads have had a valve job(s), then the valves are set into the seats further and shimming will be required to get consistent seat pressure. Other things that you'd have to know include length of valve stem (some factory valves had anti-rotation devices that affect spring height, desired seat/open pressure, coil bind height, etc.

If you're not sure, then I'd really recommend pulling the heads and taking them to a reputable machine shop. The shop will have the specialized equipment needed to measure the installed height, check for coil bind, etc. Personally, I'd never do a spring swap with the heads on the car unless it was an absolute emergency. I like to have everything absolutely correct (seat pressure, locks, etc.).

[Old Guy with 87 GT]

thanks for the reply .....it kinda is an emergency......i drive the car daily and i don't want the valve float to get worse or do any more damage to it ......i'm worried i'll float a valve into a piston or bend one with an accidental over wind........i'm kinda strapped financily thats why i'm doing them myself with the heads on the car ....i can't even really afford the new springs ,but i sqeezed my budjet down enough to get them anyway

is there any way to measure valve stem height or the installed spring height...... could i install springs and micrometer top to bottem of springs to set each one equaly......hopfully i'll be ok with spring pressure and spring bind ,the kit i got i'm told is sufficient for more lift then i'm going to have ....is there any way i can check open spring pressure

man, at this point i'm frustrated enough with this car to sell it and by a yugo .....or even worse ...a camaro....