The 351 cam out of the Bronco is a flat tappet hydraulic and
very mild.

I THINK your 83 is a flat tappet also? Then it'll fit right into
the 351. Just remember to keep the lifters matched to the
cam lobes they're on now.

The 5.0 heads will bolt on, but the head bolt holes thru the
heads will need to be drilled out for the larger 1/2" diameter
351 head bolts, and you'll of course need 351 head bolts.

The rings and rod bearings will fit, but the 351 mains are larger
diameter.

The gaskets will all fit.

You didn't ask, but your 5.0 intake is narrower than the 351.
Probly cheaper to buy a used 351 intake off ebay than buying
the kinda spendy www.pricemotorsport.com adapters.

You'd also need a 351 distributor.

All your front accessories including water pump etc will fit on
the 351, (you need the Ford 351 PS or AC/PS combo adapter
mount to use your 302 PS or PS/AC) but I think you do need to
get the 351 damper and flexplate or flywheel from the Bronco.
Some year, 302's changed from the 28 oz balance to a 50 oz balance,
don't remember when that was, but I think it was before 83.
You could probly look up in O'Reilly's online catalogue, or Autozone,
and tell by looking at your stock application, or look on an aftermarket
drivetrain or auto trans builder website.

I put together a mild 351 Lightning motor (stock shortblock) with small
port/small valve Edelbrock heads, Cobra intake, and stock 5.0 HO
hydr roller cam with 1.72 rockers to use in a heavy car for lots of road miles,
only 3.55 gears and a 2500 stall automatic.

Got the low and mid range torque plus good mileage I was after,
but the hp really suffered and it runs out of breath by 5000 rpm.
I got about a 50 lb torque increase but virtually no hp increase
cuz of the small (even for a 302) cam & heads.

I did a little write-up on the details of my swap -

http://www.lincolnsonline.com/tech/00144.html

Very good info. All 351Ws are 28 ounce motors. I think '81 was the first year the 302 was 50 ounce. '82 was 50 ounce for sure, as were all subsequent 302s.
255s changed differently. Avoid 255 stuff.

macx said:

but I think you do need to get the 351 damper and flexplate or flywheel from the Bronco.
Some year, 302's changed from the 28 oz balance to a 50 oz balance,
don't remember when that was, but I think it was before 83.

Click to expand...

headers

If ya do decide to upgrade to the 351.. I've got a brand new set of Hooker Hustler headers that we were going to use until we decided to go with an AOD .. they will fit 79>93 fox body with the 351 swap.. c4 or manual trans only .. If your interested e-mail me at .. [email protected] .. steve