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I have a '78 with the 2.5" wide TRW 355# fiberglass spring. Yeah, don't get me started on the ride height issues
Will a 2.25" wide (77 and prior) VB&P fiberglass spring work in its place?
I guess what I'm looking for is thoughts on if the extra (or lack of) .25" of a inch critical? (1/8" per side) Maybe a new spring cushion? A spacer of some kind? Looked on the VB&P site for a "spacer", but couldn't find one, even if one exists. Lots of info here on the springs, rides, installations etc, but couldn't find anything on the interchangeability of the two widths.
The VB&P Spring will come with its own hardware kit. It makes no difference what spring You have now. If you are replacing a VB&P with another VB&P you can order it with out the Hardware Kit, but that is a special order, not whats in the catalog.
There are spring plates/spacers available that were used with 2.25" steel springs in certain years when the narrower spring was installed in the 2.5" differential. Would likely work with the narrower fiberglass spring.
Spacers would work. Not understanding why you want to go with the incorrect spring though? available rates?
Price and availability in Found a good used spring for a good price and a second one, a couple years old but only used to roll a chassis in and out of a garage. One is 2.25" and the other is yet to be confirmed
By the time I order from a vendor, ship it, taxes, boarder fees and dollar exchange its crazy expensive.
The VB&P Spring will come with its own hardware kit. It makes no difference what spring You have now. If you are replacing a VB&P with another VB&P you can order it with out the Hardware Kit, but that is a special order, not whats in the catalog.
Hopefully I'll hear from VB&P on this soon. So If i understand correct all springs are the same width, just the mounting surface (rubber or whatever) dictates the width?
Originally Posted by revitup
There are spring plates/spacers available that were used with 2.25" steel springs in certain years when the narrower spring was installed in the 2.5" differential. Would likely work with the narrower fiberglass spring.
Those vertical spacers would work for steel, not a FG spring.
I think the "plate" that mounts between the spring and the diff cover is what dictates what spring goes in what year of car. 77 and earlier the "plate" would be 2.25" and 78+ is 2.5"
Im wondering if I just get a '78 "plate" the spring that was previously mounted on a 71 (for example) would fit, because its the plate that is the correct width, not the spring itself.
Hopefully I'll hear from VB&P on this soon. So If i understand correct all springs are the same width, just the mounting surface (rubber or whatever) dictates the width?
Those vertical spacers would work for steel, not a FG spring.
I think the "plate" that mounts between the spring and the diff cover is what dictates what spring goes in what year of car. 77 and earlier the "plate" would be 2.25" and 78+ is 2.5"
Im wondering if I just get a '78 "plate" the spring that was previously mounted on a 71 (for example) would fit, because its the plate that is the correct width, not the spring itself.
The spacers work just fine. The important thing to let VB&P know is the dimensions of the rear diff mounting. Factory 78 = 2.5"
So you have 2 options.
1. add spacers and use the VB&P 2.5" plate to match the diff
2. replace the rear diff cover with a 2 1/4" diff spacing and use VB&P 2 1/4" plate.
My 78 . I have been running the 2 1/4" spring for 5 years including 10 track days a rear without any problems.
Last edited by cagotzmann; 10-05-2017 at 11:02 PM.
I think probably GM mixed and matched the 2 1/2" and 2 1/4" diff covers and springs around the '77/'78 model year changeover, using up what diff covers they had on hand, using those spacers where required. Those were OE on some cars right?
We don't handle the 2 1/2" wide rear spring. All of the composite rear springs that we manufacture for the C2/C3 cars are 2 1/4" wide. We have made & sold this type for 1963 through 1977, '78 & '79 & '80-'82 for 25+ years. There is no "scissoring action" that would tend to move the tips of the spring forward. The normal steel mounting plate works fine on all, for the particular year(s). Our 3 piece center mount pad set #P1-403 = $18.99 will work fine on the 360 spring. This will go right in on a '78 or '79 rear end cover. We like the 8" fully threaded spring bolts with nylock nuts to give a full range of ride height adjustment. These C-3 cars usually sit at about 27" or 27 1/2" from the lip of the wheel well openings to the pavement. You can adjust up or down to suit your needs. We have the center mount set, as well as, the spring cushions for out at the tips, in stock whenever you need. These are small & could go via USPS. Feel free to email or call anytime.
We don't handle the 2 1/2" wide rear spring. All of the composite rear springs that we manufacture for the C2/C3 cars are 2 1/4" wide. We have made & sold this type for 1963 through 1977, '78 & '79 & '80-'82 for 25+ years. There is no "scissoring action" that would tend to move the tips of the spring forward. The normal steel mounting plate works fine on all, for the particular year(s). Our 3 piece center mount pad set #P1-403 = $18.99 will work fine on the 360 spring. This will go right in on a '78 or '79 rear end cover. We like the 8" fully threaded spring bolts with nylock nuts to give a full range of ride height adjustment. These C-3 cars usually sit at about 27" or 27 1/2" from the lip of the wheel well openings to the pavement. You can adjust up or down to suit your needs. We have the center mount set, as well as, the spring cushions for out at the tips, in stock whenever you need. These are small & could go via USPS. Feel free to email or call anytime.
Sincerely,
Gary
I concur...I have a VBP 360 monospring that I installed in 1986 still on the car...2.25' inch wide...zero issues even today.
I think probably GM mixed and matched the 2 1/2" and 2 1/4" diff covers and springs around the '77/'78 model year changeover, using up what diff covers they had on hand, using those spacers where required. Those were OE on some cars right?
GM did not mix and match the differential covers and springs, during 77-78.
The standard 9 leaf spring was increased to 2 1/2" wide in 78, and the rear cover and mount plate were changed to accommodate the wider spring. The 7 leaf spring included with FE7 Gymkhana Suspension, was unchanged for 78, and remained 2 1/4" wide. The spacers were used to properly fit the 7 leaf spring, to 78 and later cars, ordered with Gymkhana Suspension.
GM did not mix and match the differential covers and springs, during 77-78.
The standard 9 leaf spring was increased to 2 1/2" wide in 78, and the rear cover and mount plate were changed to accommodate the wider spring. The 7 leaf spring included with FE7 Gymkhana Suspension, was unchanged for 78, and remained 2 1/4" wide. The spacers were used to properly fit the 7 leaf spring, to 78 and later cars, ordered with Gymkhana Suspension.
My '78 is a FE7 car, 7 leaf, 7/16 sway bar etc. When I replaced the old spring with a new 7 leaf, I'm pretty sure it was 2.5" wide. The TRW "i got a deal on" (of course) is 2.5, IIRC.
I guess I need to crawl under and triple check (again).
Anybody have a photo of the plate that the spring sits on?
If all VB&P springs are 2.25" (according to their email), only the plate, for lack of the correct name for the part, NOT 582714 in revitup's pic above) then I just need the correct width plate to mount to the 2.5" wide diff.
10-04-2017, 10:00 AM
Fiberglass spring width issue
