I am having valve springs replaced in 1965 401 Nailhead out of a Wildcat. The engine is being rebuilt to stock with .040 pistons being the only mod. Northern Auto Parts lists Sealed Power valve springs part # VS612 (outer) & VS527 (inner) as replacements and don't give much info on them and they are special order. Russ Martin offers two sets of springs one is a replacement set and the other described as a softer set to allow for higher RPM. This engine will be used in Streetrod not for track. Looking for advice on which springs to go with as I don't see other sources listing them (at least not as 401 replacements). Comments appreciated. Al Tornabeni.
i had a 401 that used stock springs with .060 shims under them, that would go to 6000 rpm and not float... that is as high as you go with a nail,,, period.... they are not rpm engines.... imho money spent on special heavy duty , extra stiff springs is wasted money.... but you want good quality springs... a set of new stockers would work very well.... softer for higher rpm ????? nope.... stiffer for higher rpm....:Brow: but,,,,, stiffer increases cam friction and heat....Toms rockers cures this problem....
I would call comp and see if they make a behive spring that would fit.. get the best of both worlds. Doc and a few of the other guys might now better how much you can machine out of the spring pocket if needed.
I know Tom uses Chevy springs with some machining - LS1's? He's been quiet recently but maybe he'll jump in here
I had the same probelm did some research on the site and Walt found some Isky springs that are drop in replacement# 1005-w outer and 1006-w for the inner spring. My engine builder was impressed with the selection that I found for my app. it will be a seat pressure of 110 and open at 285. hope this helps. the thread I got this from is BIGGER VALVES SMALLER STEMS started by GSGTX (JOE)
I have been using ls1 beehive springs for years. No machineing was done. just droped right in. They are set up for 125 seat and 305 open if I remember right. Comp carries the springs.
I'm using Sbc Comp 994-16 1.437 inch dual valve springs with a dampener in my Nail, had to machine the heads and guides for them to fit but they're a great set up.
