Broken valve spring


Veteran Member
Lifetime Gold Member
Sep 15, 1999
Ontario, Canada
After breaking 1 spring in my roller 1970 LT1, I changed them all to the same Lunati part no using the twist tool. I’d like to get the tool that screws into the stud and has a 1 arm bandit but the reviews suck.

What I used along with compressed air. And no I did not go to TDC for each valve. It takes long enough without the TDC step.
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Veteran Member
Jun 17, 2006
A drop-in valve spring-retainer kit from Alex's Parts can be a good option which does Not require any machinework. Also, google "ghetto grind" for a DIY job using aftermarket "Z28" springs on Vortec heads.

It's an old wives tale that you MUST ALWAYS machine the guides/guide boss ... wrong. All depends on choice of retainer and springs. Some folk didn't confirm if their valve stem seals are firmly/correctly seated ... doing that may yield a lot more retainer-to-seal clearance.
On Vortec heads it can be scary deal though. I had one set that only has .455 clearance and another set of 906's that had almost .500 the best retainers are the LT4 ones. Nice and light with a little extra clearance. I just do all my head when they are off and cut down an extra .080-.100 to be on the safe side.


Sep 5, 2001
South of Dallas TX
Comp Cams, and maybe some others, have an online tool that will help you select a cam. You can call Howards and speak to one of their tech guys, I've done that before.

You can change springs with heads on and in the car. Some use compressed air to keep the valves up. I lower the piston, put about 18" of cotton rope through the spark plug hole, and manually turn the engine to where the piston has the rope pushed up against the valves. If you search UTube, you fine several videos on this subject.
This does work. A little clumsy and slow but gets the job done.


Veteran Member
Lifetime Gold Member
Nov 4, 2004
Ringgold, GA
I have both tools COPO is showing, one with the arm works quicker and is easier. I've had it for several years and it didn't cost near the current price.


Veteran Member
Oct 9, 2020
I have a manual VS compressor tool that a T&D maker pal o' mine made for me nearly 45 years ago. It began as a new, large, USA industrial quality C-Clamp which was in stock at the plant he worked for. Pal cut it in-two and then welded-in an extension to its overall height. He turned & welded a collet for one end to set atop valve retainer. Pal gifted me this tool with intended use on Harley V twins (we shared that addiction). The collet has side "windows" thru which there's plenty room to reach in to retrieve or set keepers. Somehow, the retainer collet somehow fits (well enough) dang near everything else. I've used it on many other motors. To clarify, with this type tool, head Must be separated from block/cylinder. Thanks Mike Ochs ... where ever you may be ... hope ya always have a decent cigar to chomp on!


Veteran Member
Sep 8, 2015
Made these (roughly, in both ways) 35+ years ago, scrape bin metal, still use them today.


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Veteran Member
Sep 8, 2015
I need 2 hands when fiddling with the locks and is why I couldn’t use the 1 hand press tool.
I think we were more dexterous 40 years ago.

Same here, but, to help out when alone, I've been using my small Snap-On mini flat screw driver with a magnetic tip on the end, it's actually quicker doing that way and alone to boot.

Works perfectly when doing the springs changes on the dyno or in car, picks the the valve lock apart, spread and turn to the loose side, then use the magnetic side to take out the keepers, and they do not fall off.

Use the same mini screwdriver to "time" the keepers as well when reinstalling, and all alone is quickest.

Valve lock buddy.jpg

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