CLASS RACER FORUM - View Single Post

ron mattson · 12-02-2013, 03:01 AM

487/487x and 993 are all based on the same
Casting group, that is why some have dual
Numbers top and bottom. As far as flow I have
Seen more of a difference between individual
Castings than between casting numbers, have
Seen good and bad 487 or 993 just depends
On the casting more than the number.

12-02-2013, 03:01 AM	#6
ron mattson Member Join Date: Nov 2005 Location: cloquet mn Posts: 467 Likes: 17 Liked 68 Times in 31 Posts	Re: 487 vs. 487x heads 487/487x and 993 are all based on the same Casting group, that is why some have dual Numbers top and bottom. As far as flow I have Seen more of a difference between individual Castings than between casting numbers, have Seen good and bad 487 or 993 just depends On the casting more than the number. __________________ Ron Mattson 5015 STK