Mods to make the chev 305 pistons and rods fit 250

Unfalconbelievable

Well-known member
OK I know a 56 thou overbore is required to make the pistons fit in the bore but what compression height should i get so I come out with close to 8:1 compression with the EFI head? And what has to be done to mate the bigends to the crank, mill the rods out, fit bigger bearings or grind the crank down?

THANKS ALL
 
The 250 has a terrible rod length. Why would you want to go to an even shorter Chevy 305 rod? Why not just enlarge the small end of your stock rods?
 
Why do I want chevy rods???? Because 250 rods tend to bend at about 350hp and I'm looking for 500+hp. And I'm pretty sure you can get longer than standard rods to match or maybe even improve on the 5.88 of the 250. Chev have a huge range of aftermarket performance parts
 
Have you thought about rod bearing width, and clearances between the side of the rod and the crank?

What about Ford 300" rods? Longer, stronger, simpler fit.
 
I know its been done before so they must be similar and the 305 came out with TRW forged rods so they're cheap for forgies. I'm in aussie and there was never a 300 released here, so expensive, longer and easier is the way it works for me! Also has anyone tried using say a 6mm (240thou) copper head gasket to increase deck height enabeling the use of longer rods while still maintaining heaps of meat in the crown. I know this was done in the engine masters challenge for a cleveland V8 with a 300thou head gasket being used to bring the clevos 9.2" deck up to the windsors 9.5" so they could use CHI clevo heads but keep good rod/stroke ratios with the stroked bottom end. How hard could it be? A set of chev 6" or 6.1" rods in a 250 crossflow would be great!
 
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