350 to 383...

[Chevelle454]

Does a 350 block need to be clearanced to make a 383? I have heard they need to be "notched". Others say you only need to get the 400 crank main journals down to 350 size? What is needed to make a 350 a 383?

Thanks

[bigjimzlll]

You need to clearance the pan rails to clear the rods..you may also need to clearance the rods for the cam. You will need a 3.75 stroke crank..either aftermarket or have a 400 crank cut from 2.65 to 2.45 main journal size. If you use the 400 rods you can use 350 pistons. If you use 5.7-6" rods you need special stroker pistons. If you go externally balanced you will need a 400 harmonic damper and flexplate/flywheel..Dont skimp on the machine work and use the best parts you can afford. Measure (or have measured)all bearing clearances. Before you start, have the block tanked and magnafluxed.

[Chevelle454]

Does anyone have a picture of what the block looks like clearanced? What's the cost to have a machine shop do the work, or could I do it myself. Where is a could place to get a stroker kit for the best price?

Thanks in advance...

[lock]

When I did my build, the crank only hit in the one location. Basically you just gind down until you have a thick paper clip clearance. Not hard to do, jsut mock it up and turn the crank checking for clearance issues on the pan perimeter and the lifter jounals.

[Chevelle454]

So the counterwieghts only hit in one area? Can an angle grinder be used?

Thanks

[crazy longhorn]

Sorry, no pics at any rate, my 383 runs a scat crank, & factory 5.7 rods. there are notches below the bores(factory), & these were ground for clearance on the longer stroke/longer rod. the panrails didnt seem to be a problem, but just above the panrails.....the old 6 Q truck pan was also heated & clearanced in 3 places(below the pan rails) for the rods. The factory 350 rods were prepped & "cam clearanced" (top corner of all 8 rod bolts that swing past the cam). I have heard that a stock 400 crank, with the mains ground to fit the 350 block, & the stock 400 (shorter rods) will clear in most cases. The biggest trouble with the short rod setup ,is that it causes more side loading on the pistons(more friction & wear), as well as eating some power up! If i were to do another stroker, i think i would opt for the 6" long rods & go internal balance. Initial cost may be a little more on parts, but in the longrun I think it would be money well spent. Best of luck,crazyL

[lock]

All block casting at a little different. Mine only hit in that spot. I used a die grinder to take off the excess.

You can find decent budget kits at strokerkits.com and powerhouse(forget the url) .. make suure you get it balanced though.

Originally Posted by Chevelle454

So the counterwieghts only hit in one area? Can an angle grinder be used?

Thanks