Will the LT4 Valve springs fit into a stock LT1 head?
Can you put aftermarket retainers on them?
What other parts are needed to change the springs?
How hard is it to change the valve springs with the heads on the car?
Any special tools to make it easier?

Thanks

 

donno.

I would use stock LT4 retainers.

New pushrods... and roller rockers. I would also get new valve cover gaskets.

It can be tricky....

oh, yes. There are a couple of tools... one is a contraption that will allow you to pump air into the cylinder to hold the valves in place. otherwise, they will fall through. you will also want to get a valve spring compressor.

anytime.

 

1) Yes the LT4 springs fit.

2) I've never seen aftermarket retainers sized for LT4 springs. The OEM LT4 retainers are lightweight, I'd stick with them. The only time you really need to spend the extra $$ for Ti retainers is if you're going to beat on the engine and regularly spin it to near 7000 rpm. An LT1 will experience piston ring flutter around 6400. In addition the LT1 valves are too heavy for the LT4 springs to safely go repeatedly much beyond 6300. LT4 valves are hollow stemmed for reduced weight.

3) No other parts are needed although most people will replace the valve seals at the same time. Typically the springs are done during an upgrade to 1.6 roller rockers versus the OEM 1.5 stamped rocker arms. If you buy 3/8" self-aligning roller rockers, then you can reuse your pushrods and rocker arm studs.

4) Here's a link to a write-up I did... http://www.grandsportregistry.com/te...ve_springs.htm ...it's easy, but can be tedious. Instead of filling the cylinders with compressed air to support the valves, you can also rotate the engine such that the piston in the cylinder being addressed is at top dead center. By doing so, if the valve drops it only goes about 1/4" and rests on top of the piston and you can pull it back up. Make D*MN sure the piston is at TDC 'cause if the valve drops and the piston is down in the bore, you'll be pulling the cylinder head to retrieve the valve.

5) Summit sells a valve spring compressor for $50. It's a "must have". There are various types, but I like the stud mounted style the best. Don't use an old style compressor that prys on the cylinder head as that can mess up aluminum heads. There's also a screw type compressor that mounts over the spring but that type has always looked like a pain to use when trying to set the locks.


[Modified by 96GS#007, 7:26 AM 11/19/2003]

 

96GS, glad you gave the guy a straight answer and saved this guy time and money.

Why would someone advise him he has to change retainers, rockers, pushrods etc.. just to install new springs.