mhuppertz

So, since I have fuel galore now, is a moment of ebay weakness I bought a 4,200 spring. It was cheap, but now I will have to get 60lb springs right? Shoulda thought it through, but I occasionally bang against the 3,200 spring and probably need 60lb valve springs anyway don't you think?

Free89W350

From what I remember reading you will need the 60lb valve springs on at least the exhaust side but while your in there you might as well put them on both sides then you will never have to worry about them again. They can be had pretty cheap but you have the labor time in doing them. I would say go for it and let us know how it works and how it feels reved up that high.

mhuppertz

Got to save up a bit. I can do them whenever I do the head gasket. Still have to buy the gasket itself, but I have the studs and taps.

jimbo486

You should do all of the springs. Just doing the exhaust side will only protect the exhaust valves when using an exhaust brake. With stock springs, the valves are known to start floating about 3,600RPM but they would work fine as long as you don't push them. You may be able to postpone the expense (if money's an issue) for a bit while you save up some cash.

Be careful when you order some. A lot of places I've noticed sell them in sets of 6 so you'd have to order 2 sets, of course.

mhuppertz

Yea, I noticed that. I wonder if the extra seat pressure will affect efficiency?

92smokin blacky

I got a 4200 governor spring and haven't changed my valve springs out for 60 lb ones... yet anyways. I've just been driving mine nice and watching my tach, I've kept it under 2800 easy enough. I'm gonna do studs and springs at the same time when i get more money (if it doesn't end up going into something else on this truck or in my fuel tank)

The 4200 spring is way touchy and it will fuel hard and take off from about 11-1200 rpm to 2200 rpm and then on higher. It just takes right off though after you hit that sweet spot. I've been happy with it and like it, you will need to re index your throttle shaft one notch once you put it in though so it will idle.

ARbowhunter7

Or you could just return it and get a 3,200 rpm spring. Have you ever seen a flow bench test on a VE pump? These things are useless over 3K rpm.

BC847

Or you could run the 3800rpm spring. Bosch P/N: 1 464 650 374.

If you plan on running around there with more than 40 or so lbs boost, you might reconsider the 60# valve-spring and go for something better. (Increased boost adds to the tendency to float the intake valves for example).

And while the VE's power does roll-off a LOT after 3000 or so, there's still a lot that can be had at 4000 or so. I've managed over 400HP to the ground at 4200 with an automatic.

mhuppertz

I run a 3,200 spring now with about 40PSI. I know my pump is a limitation, and so is the stock flow (or lack thereof) of the crappy head. But I'm thinking a 4,200 spring will let me pull hard to 3,200 with no defueling.

soggy

I run a clipped 3200 spring, it showed no signs of dropping off at 3500, which is where I let out of it. IMO there is no reason for a 4200 spring.

mhuppertz

It was cheap. This way I will know exactly what RPM it defuels at.

pwrtripls1

Let us know how you like it. My new pump will have a 4k spring. While I have the head off I should swap in some 60lb springs. The less I have to shift at the track the better, so the added rpm range will help out. Even though power will be falling off, its still faster than having to shift near the end of the track.

mhuppertz

saving up for springs, gasket, and a head!

92smokin blacky

the 4200 spring picks up and goes alot quicker if you ask me, anything after 1200 rpm and you better be hangin on. It is touchy. Be great if you run a big single to get things goin