I was talking to a guy the other day (whos knowledge is well know) and he said that you could take a 351w block and throw in a 400 crank with 351w rods and 302 pistons and get a 400 in a small block bolt pattern. that way i can keep my stock tranny and such. Just curious if anyone else had heard of this and if so how much work is required to make it fit
400 crank, machine the nose, turn the rod journals down to 2.100" use 5.7" 350 chevy rods and stock 351w pistons. Brings the package to 9.479" and the deck height of the early w blocks is 9.48...later ones are 9.50".
that's the OLD SCHOOL way to make a 408. Rod/stroke ratio sucks and the 5.7 rods are weak. By today's standards, it ain't worth it. You can buy a powerhouse kit for $699 now and be done with it.
Thanks to SlowFord for the link; http://www.fordmuscle.com/phpBB/repl...31500&forum=12
If you read the article and still want to make a DIY 408w stroker on a budget you might try this:
The articles describes most of the block and crank mods. The only thing that needs precision machining is the 'snout'. Any crank shop should be able to do that and grind the counterweights for a lot less than a new stroker crank. Start with a truck or van 351w. You can reuse the 351w rods (5.956 long) and 289/302 pistons (ie. Clevite "1157 or 1177 with a 1.585 c.h.). Use a .040 head shim & gasket with the original heads to keep your quench height and you'll be under 10:1 compression. The rod ratio isn't great but its better than a stock chevy 400. If some one sold a modified 400 with only the snout and weight mods (for a decent price) I would use it but to me even $500 is too much (not just cheap, poor too!)
Never accept \"You can\'t do that!\" until you try.
It costs $350 locally to have a crank offset ground. Machining the counterweights is by the hour. You can grind the counterweights with an angle grinder - I'm sure you can machine the same amount off of each with your eye so that the crank will balance evenly.
It's way cheaper to just buy the right part, either a properly modified crank or a Scat model.