windsor timing chains
 

Hi, can anyone tell me the difference between pre efi and efi chain sets. i'm fitting one now and the chain seems very close to the block, i think i've been supplied the wrong set. it's a carbed engine so that's what my supplier gave me.

The only difference I know of is the eccentric drive on the front for the fuel pump is omitted in the efi set, both are double rollers, the chain and gears should be the same. Do you have the thrust plate on correctly? Make sure the gear is facing the right way too.
Goodluck, Charles

yes the gears and plate is on right with the oil feed slot over the oil feed hole. was wondering if the gears had a different step machined on them for efi blocks or if block castings are different.

Well not that I'm aware of but they might be different, one way to tell is to call your local Ford dealship's parts counter and see if the part number is the same for the 2 gearsets. I would think the blocks would be very similar but then again Ford has been known to change things around a bit. Pre 85 blocks had no provisions for roller hydralic lifters hold downs and they went to fuel injection in 87 so depending on how old your 351 block is there maybe a difference in the thrust plate area.
I'll keep digging around and see what I can come up with, Charles

The chain sets are the same. With some of the double roller sets you will have to grind a little off of the thrust plate. You will also need to watch the length of the cam dowell pin. Depending on whether or not you use the fuel pump eccentric and which eccentric you use and the combination of the gear and cam you may have to modify or use a different length dowell pin. Make sure the pin isn't too long and not allowing the cam gear bolt to properly tighten the cam gear. Don't worry about the chain being close to the block, it will run a lot closer than the stock chain because it's wider. There is very little end play on the Ford cams and it won't get any closer than what you have when you build it.