XY 250-351 conversion question - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

ogion · 02-11-2002, 00:39

G'Day,

I'm gunna convert my XY 250 to a 351. I have a toploader and my front suspension done. Disc brakes for the front end are a must, and I'd need a clutch, bellhousing, flywheel, and of course a complete motor. Apart from that stuff, would there be anything else I would need ? Would the old diff be alright to run for now ?

02-11-2002, 00:53

Diff should be fine so long as you don't do any burnouts.
You may need to change the tailshaft as well unless the top loader is already bolted behind the 250.

botch · 02-11-2002, 02:51

ive done a few of these conversions and im probably just stating the obvious but here goes..

v8 engine mounts
v8 starter (you will need the aluminum spacer, normaly $30 worth for a manual)
different throttle linkage, unless your already running cable
fuel line on a v8 comes out a little hole infront of the shock tower, not behind like 6's do
v8 radiator
exhaust mods etc

The slave cylinders are the same on xys for 6 and 8 cylinders.

when you get the bellhousing make sure that there is two threads in the housing for the clutch slave cylinder to bolt onto. The later models xd...etc had a hole and ran a clutch cable. these will not run a slave cyldiner

BY THE WAY, welcome to FF!
:s2:

smciner1 · 02-11-2002, 02:56

I was wondering when you would find this thread botch......
Don't forget! A larger 3/8" fuel line for a 351.

Forte · 02-11-2002, 02:57

A mate did the same thing to an old 250 xy and didn't have any trouble with the diff at all but he used a c4 auto.The 351 had a bit of a cam 650 holly and extractors twin system.It lasted years and we used as a work parts chaser (lots of different drivers):s6: :s2: :s3

Road Warrior · 02-11-2002, 04:39

Yeah I've done a few of these and I have learnt my lesson - buy one that is already done, you will save $$$.

Basically what Botch says, you will need the V8 specific engine plates (the ones that bolt to the chassis), the V8 throttle rod (unless you go cable). If you look closely on the firewall there are two little dimples where the throttle rod is meant to bolt. Upgraded triple core radiator is a must, along with the appropriate cooling fan (yes it matters). Change the fuel line, an et hold of a V8/manual trans spacer plate (thin plate that goes between bellhousing/block).

Ummm....thats about all I can remember. I'll have to refer to my Ford Parts Catalogue (XW/ZC) for any other bits...

smciner1 · 02-11-2002, 05:06

If you are going to run a Cleveland, like RW said, you willl ned a big radiator. A clutch fan a shroud make heaps of difference too. It should stay cool then.

Falchoon · 02-11-2002, 15:39

The 6cyl radiator will keep a 302 cool but not a 351. Outlets are in the same spots. Buy the biggest and best radiator you can possibly afford the first time. I had a triple core in my XY 351 and it would still run hot in traffic, even with shroud, Fairlane 6 blade ircon fan and thermo. Some people use later model crossflow radiators, supposed to more efficient, depends how original you want to stay.

smciner1 · 02-11-2002, 18:22

Probably a 302 Windsor, but not a 302 Cleveland.

Falchoon · 02-11-2002, 18:37

I re-powered my 250 XY with a 302C and drove around for ages with 6 cyl radiator, don't think I changed it until I dropped the 351C in. 302W radiator has outlets on other side if memory serves me correctly.