FoMoCo

i just wanted to know if there would be any performance gains if I swapped my stock 5.0 heads for some 351w heads. I have a 351w (non roller block) and I wanted to know if they would work at all. Or at least point me in the right direction if you can.

gspfunk

The bore for the bolts or studs are a different size (5/8 instead of 7/16, I think...), but people run them on 302's. You'll have to drill/tap your block for the bolts/studs or find spacers that fit in the holes.....

Black Snake

Eddelbrock sells shim kits so you can use the 7/16s bolt.

mcfomco

Thats what i was gonna say guess im to slow.[:@]

FoMoCo

so i guess you guys are saying to go for the swap. what are the differences between the heads.

uedlose

what year heads are they

FoMoCo

i have no idea. i just have the motor. It has an original 2 barrel carb. I guess i need to run the numbers on the block. Why would I need to know this?

uedlose

if its a new motor or even some of the older ones they are no better then what you got I think it would need to be like 74 or older to be much help unless they off a lighting.

Joel5.0

If they are '74 heads, pending you check their casting number (C0OE-B, C9OE-D, D0OE-x or D0OZ-x), you'll have 1.84"/1.54" size valves over the regular 5.0L sizes of 1.78"/1.46". '78+ 351w heads are similar to 302's. Need to check those casting numbers to confirm it though.

tinman

351W heads that start out with the #'s C9 or D0 would be the ones to find.
Even then I don't know if you'll see much differance in the performance....