What do I have?

[Ford68Pony]

I have asked this a couple of times on different forums and really didn't get a definative answer on this. I converted my v-6 mustang to a v-8 but I really don't know what v-8 I have.... I pulled the engine out of an 84 mustang. I ran the numbers off the block and it was origionally a 302 out of a 68 Galaxy. The funny thing is that the firing order is for a 351 and it also uses the 45mm spark plugs of a 351 but the heads do no look large enough to be a 351... I've inserted a pic to help assist. Thanks to anyone who replies or takes the time to read this post.

J. Vamos

 

[Max Power]

The block may be a 68, but you probably have heads off a later model. Firing order is determined by the cam, so anything could have been put in there. Judging from the oil pan, somebody took an older model 302 block and fitted later model externals.

 

[68torinogt]

the 351 and 302 look like the same engine for the most part but i would say the 302 block and internals are 68
i doubt it is a 351 unless its a stroker from a 302

 

[65ShelbyClone]

he funny thing is that the firing order is for a 351 and it also uses the 45mm spark plugs of a 351 but the heads do no look large enough to be a 351... I've inserted a pic to help assist. Thanks to anyone who replies or takes the time to read this post.

Firing order is only determined by the cam. The 289/302/351 Windsor cams all interchange, so it's an easy way to change to the H.O./351W order. The heads for 289s, 302s, and 351Ws also all interchange. 351 Cleveland heads are slightly larger(and a fair bit different) than the W heads, but they still can be interchanged(that's where a "Clevor" comes in...351W with big 351C heads). Also, the modern small sparkplugs are 14mm; the bigger, older ones are 18mm.

Anyway, going by the picture I would say that engine is a 302.

 

[Ford68Pony]

Thanks for the input. I asked one of my buddies about it a while ago. He informed me it was probably the old block with newer parts (He said ford switched to the 351 firing order on all it's newer v-8's (Late 70's early 80's and later cars) cause it caused less stress on the cam). I didn't know how well his info was because he was high when I was talking to him.

 

[65ShelbyClone]

He informed me it was probably the old block with newer parts (He said ford switched to the 351 firing order on all it's newer v-8's (Late 70's early 80's and later cars) cause it caused less stress on the cam). I didn't know how well his info was because he was high when I was talking to him.

I've just heard that the HO firing order eliminated the possibility of the 4 & 5(ot 7&8?) plug wires from crossfiring or getting mixed up and causing 90* preignition between cylinders. I've heard of a few shattered pistons on stock truck 302s from that. Whether or not that was the reason for the switch, I don't know.

 

[D.Hearne]

The switch in firing order was originally to revise the stresses on the crank and journals of 351's. Nothing to do with spark plugs or wires, if that were the case, you'd now have problems with numbers 5 & 6, instead of 7 & 8. The switch in 302's stemmed from Ford's taking an off the shelf cam ( from the 351 marine engine) to use in the then "new" 302 HO introduced in the 82 model year Stangs. It was simply carried on from that point forward, in the HO engine only. The std or base 5.0's in the Crown Vics, Marquis, Lincoln Town Car, pickups, and vans still used the old firing order until 1994 when the pickup/van 5.0 got the better F4TE roller.

 

[bnickel]

you mentioned that the spark plugs were the larger "351" plugs but in the 60's the spark plugs were all the larger style. they didn't switch to the "peanut" plugs until the 75 or 76 model year.