Hi all I am just about to fire this thing up (late style 261 chevy) with new PG valves installed but I got a quick question about the 455 buick springs that are being installed as we speak! I got a set from the local machine shop and at first glance the spring-buick 455 that is, that I was givin is NOT taller than the stock 235 spring, I thought the correct 455 WAS taller than the 235 spring? Any info here would be exceedingly helpful as I dont want to ruin this motor with incorrect springs. Are there two different length 455 springs with one of them being shorter? my cylinder head guy says it looks 60 thousanths shorter than my stock 235 spring. I really dont want to run a marathon and trip at the finish line. Thanks in advance!

Hi dbane261 . . .

I am not sure that I am following you here. Are you simply comparing the uninstalled height of the two different springs?

This measurement doesn't really mean much as the underlying 'wire' used to create the springs can be very different. Typically one measures the 'pressure' exerted when the spring is installed with the valve 'on the seat' and then one measures pressures at various levels of cam/valve lift.

If the spring pressures are 'lacking' one can shim the spring to a shorter installed height - but this has limits as one needs to avoid coil bind on the other end . . .

Have you compared the difference in pressures at installed height?

regards,
stock49

The spring you should be using is a spring for a 455 stage I Buick. I looked at some of my motor building notes and the ones I have used in the past were TRW VS 1020. should be like 100 to 110 lbs on the seat with the valve closed, about 270 to 280 open at like .450 lift. I used the buick springs for a cam that was .480 lift and they worked fine no bind, and could take more but the higher lift does not get you much, the head's breathing ability peters out before it can use the lift, at least that is what my experience has been. Should have an installed height of 1.858. Not sure about retainers. I think the stock retainers will work but I remember using something stronger although I dont remember now what I used.

Sorry all for any confusion here, I am not trying to be cryptic or sound moronic by any means lol, yes I merely looked at the spring uninstalled, they are similar overall height but i thought that since the installed spring height of the 235 is 1.85 inches, and the buick is 1.90 I just naturally assumed that the 455 spring should be taller at first glance uninstalled-perhaps not lol? Just the mere look of a shorter spring at first glance really frightened me.

Your fears are well placed.

Since you have chosen the Buick spring as an 'upgrade' over the stock Chevy one - have you verified that these particular springs actually provide a higher seat pressure?

If not then perhaps you should be shopping for a new set . . . moreover perhaps your impending 'test run' should happen with stock Chevy springs until a true upgrade is in hand . . .

fears for nada, it turned out to be the correct buick 455 spring-stage 1 type after all, turns out the other buick 455 spring isnt much of an upgrade over the 235 anyhow, the correct spring more closely mirrors the spring pressure mentioned above by mdonohue05 so thanks for the info, they sure look nice on the head and flushed up PG valves look oh so pretty it was almost a shame to bolt the head on. thanks guys.