Re: 390 rebuild help
You need a 428 3.98" crank to make a 410 out of your 390. The 427 shares the same crank stroke as the 390 of 3.78". Pistons for the 410 are available in either cast, hyper or forged. Badger, Silvolite, TRW etc.. all make the 410 slugs. The 410 piston has the wrist pin location higher to compensate for the longer stroke. They are available in std bore and plus sizes for overbore. The block should be checked to see what bore it's at and if it's over .030 have it sonic mapped for thickness. You can use the 390 rods you have. Heads you have should be fine. I'd go through them anyway to be sure the valves, guides, seals etc..are cool. As far as pushrods go that depends on the cam you choose. I'll assume you have the non adjustable rockers that use the ball/ball style pushrods. Those will live if you keep the lift around 500-525. If you want more cam you'll need to get adjustable rockers and the ball/cup style pushrods. You'll also want to match valve springs to the cam. Most companies will reccomend a cam/spring package with pushrods to match. If you can swing it I'd change the rockers you have to adjustables anyway. You just need to change the rocker arm and maybe the shafts if they are worn or gauled. The stands, springs, washers, bolts etc.. can all be reused. NOTE the location of the rocker assy bolts when you remove them. One will be necked down. The necked down bolt goes in the hole where the oil feeds the rockers from the head. When you remove the rocker assy from the head you'll see that bolt hole is cup shaped and has a small hole inside it. That's the oil feed hole to the rocker assy from the head. It's the 2nd bolt fron the front on the left (dr) side and the 3rd from the front on the other side.