hi guys i just want to say that this is the best site ever been alot of help so far. now my problem. i just got springs from npd i an puting in a 454 in 71 chevelle was a 307 the springs are 3 inches shorter than the stock ones i took out. it would seem to me that the new ones would be longer or have more coils than the old ones the new ones have 2 less coils also. i called npd and they referred me to the spring mfg. when i called they were going home for the nits ill call back tomorrow. does anyone know the correct lenth for bb springs? the new ones are 15 inches long and the old ones are 18 inches. i dont have much knoledge but it would seem to me that this would lower the car 3 inches . i ordered the right springs for bb with air. also my springs are flat on one side these are round. thanks in advance. bill

You probably need to talk with the spring manufacturer. But the springs could be correct if the diameter of the wire is heavier in the new than in the old.

Three inches shorter is a lot. This will defiantly lower your car. What are you trying to accomplish. If you don’t get any satisfaction from the spring mfg., call Moog’s 800 numbers for technical info. If you can get to a Moog spring catalog it has a lot of information.

thanks for the replys. i did ck the diameter of the springs and the new ones are 1/16 thicker ,this might account for the shorter lenth. i am going to talk to the mfg today. i am replacing them because i was told that the bb is heaver than the 307 and the stock springs would have to be changed. i want to keep the stock height.i will let u know how i make out with the mfg. thanks. bill.

Contact Detroit Eaton Spring in Detroit, Mich. They have all the blueprints of the original springs and manufacture them to original specs. It would be helpful if you have a GM number for big block springs for your year, if not they can help you determine the correct ones. These people are great and very knowledgable....got new springs for my 69....I had the original tags on them, so that helped with the part number.These were for the rear....they fit perfectand the car sat exactly as new. graemlins/thumbsup.gif

thanks for the reply ,i talked to the mfg today and they said that i got the right springs,howeverwhen i talked to the man doing my control arms he said that he wasent too concerned about the lenth but the fact that they didnt have the flat end might be a problem.i am going to call eaton spring tomorrow.and talk to them im getting a uneasy feeling about these springs.ill let you know how i make out thanks again. bill