Okay, bought a set of new front coil spring from a board member a while back. Getting ready to install them in my 71. Converting from 350 to 455. The new ones are S5398. Member says they are for 455 w/a/c. He posted this link. http://www.buickperformance.com/springs.htm George N says they are for GS455 w/ac as noted in the link. I Autozone and Pepboys both have S5398 for 350 and #5536 for GS 455. I called P-S-T today. I bought 350 w/ac springs from them about 5 years ago. They pulled the receipt said I purchased S5398 for 350. He list #5536 for GS 455. So which is it? Did I just purchase another set of 350 springs? Only want to do this once!! Any help would be appreciated
hmm..you and me both good link btw, i plugged in summit 72 skylark 350 no a/c 2door it it gave me the 5536 springs...spring rate looks too much though the free height is 1 to 2 inches shorter from the oothers listed on the link you posted..
If the catalog shows the 538 springs for the 455, I would trust it. Like you say, you only want to do that job once. Ray
I have an old Moog catalog here. Lists the following; 5398: 1970-72 Skylark 350 with AC 5536: 71 GS with AC hd 72 GS 350 w/ AC 72 GS 455 w/o AC Okay, that doesn't tell us the difference between the 5398 and the 5536, so I checked the specs: 5398: 0.650" wire, designed for a load of 1678 lbs at installed height of 11.5 inches, rate= 362 lbs/in 5536: 0.690" wire, designed for a load of 1984 lbs at installed height of 11.0 inches, rate= 488 lbs/in ....Note the different installed heights, which complicates the comparison. Hard to say what the ride height difference would be without doing the calculations. But it is obvious the 5536 spring is designed for more weight and a stiffer ride. The 5536 would work better for street/strip use, but the 5536 would be better suited for optimized handling.
Well here is a question, I thought I read somewhere that the 455 and 350 are about 100 lb difference. I am putting in the 455 w/o an a/c at all. Full a/c system has to be worth a good 100 lbs, you think that might equal the equation??
just something to compare.. hotchkis 1in drop springs specs: The free length on the 1901F is 14.812 spring rate is 512lbs/" 5536 moog springs 15.06" free height 488lbs/" spring rate so is it safe to say the 5536 would actually lower youre car roughly half an inch from new stock springs...or same level as worn stock springs?
Good point Mike, I do not want to lower the car at all, infact I was hoping to increase the height a smidge to fit 255/60/15 all the way around
Catalog data at the parts stores is getting quite old. The 5398 will be great on a 455 car.Too stiff for my taste on a 350 car. Had them for a season. Bumpy ride, really jarring on a bump. I have 5536 on my '71 350 with AC. It's exactly at stock height, nice ride.
Steve, just looking at the numbers, that sounds backwards...the 5536 is stiffer than the 5398. Do you think the 350 with AC is heavier than a 455, or pretty close? Jay.... Are you looking for good handling on smooth roads (stiffer spring). Or good weight transfer for drag use (softer and taller spring)? I can't comment on the Hotchkis springs without knowing the wire diameter on them.
seems like a 350 with a/c would weigh in around 540lbs...that's still what 60 to 100lbs lighter then a 455 with no a/c(not counting ones with al heads/intakes)
Ride not my priority, but the front end remaining the same height is priority. Did not realize I have 5398's on there now that are 4 years old. Bought 5398's because I was told they were for 455
5536 is what I have. Rides smooth as a new car. The beefy swaybar & gas shocks keep it on the ground. The math looks over simplified when accounting free height, installed height, spring rates, wire diameter etc..., but believe me it is far from simple.More factors at work here. Once the spring is compressed that first inch it becomes a different animal. I went thru 3 pairs of different coils over two summers based on the math in the manuals. Had a pair from a wagon on for a couple days. Saw nothing but clouds as the front was up 3-4 "! Make contact with any one of the spring suppliers & talk to them. They know what's up & won't lead you astray. My Skylark is right at factory specs.........but.........don't forget a Skylark sits higher than a GS.
I once spoke with the folks at ESPO Spring and they seemed to be very knowledgable. Their prices are competitive as well. If you are considering purchasing new springs, give them a call! http://www.springsnthings.com/
