Unless you're looking for a VERY low rpm torque-
only motor, you really don't want that HO upper.
It's a choke even on a stock HO. And it wouldn't fit he Cobra 351 lower because the Cobra
is a round staggered port and the HO upper is a
rectangular inline port. However, the truck 351
efi lower IS a staggered round port. And it would
fit an Explorer upper which is like a GT40 type.
Here's some info -
http://www.geocities.com/MotorCity/Pit/5755/gt40p.html
http://www.mustangnet.itgo.com/
http://www.geocities.com/MotorCity/F.../Explorer.html
http://www.stormpages.com/saleen90181/explorer.htm
http://www.edelbrock.com/automotive/..._overload.html
And here's a slick one on using 302 style intakes
on 351's (to fit the complete 302 Explorer intake on the 351)
http://www.pricemotorsport.com/