Which valve springs?
 

Hi guys, just in the process of rebuilding the 781 heads I bought for my 454 and have noticed the valve springs will not transfer over from my old peanut port heads!

The stock springs on the peanuts have a cage type support around the outside and the original very old and tired springs from the oval port heads are dual with no cage!

What would be the most cost effective replacement spring that would fit the 781 heads?

When I stripped the 781's down half the springs had rotating thingy's on the bottom(technical term!!!) and half had shims! What gives?? Do all the springs need to be shimmed?
If so, what depth am I looking for?

Thanks in advance and apoligies for my technical terms!

Fixx
 

most use isky tool room springs,yes all springs have to be shimmed to their proper spring height..you will need to match the springs to your cam specs or what the mfr of the cam requires as in spring pressures...

Cam is standard Mercruiser Mag Alpha 330hp.

The rotators are not needed, however if you eliminate them you will need spacers. Either way you need to set the spring height.

You guys any thoughts on the make and model of springs I should use for 781 heads with a stock 330hp cam?

Anyone?? Am a little lost without this info!!

Summit usually suggests springs to the cam you plan on running, but if you find out the stock spring specs you can match them easily enough.