View Single Post
Old 01-12-2011   #3
Foxbody5.8
Formally Foxbody5.o
 
Foxbody5.8's Avatar
 
Location: Fabius, NY
Age: 28
Posts: 553
Liked: 128 times
Default Re: Mike's 302 to 351W Swap.

BY: macx

Starting at the top - you need a diff intake of course.
I found a GT40 351 lower and stock Cobra upper,
but Ford no longer makes them and they've gone up in price. Ebock & Trick Flow make better ones, anyway. You can use
a 302 top with the 351 bottom (match brands/types)- level of perf depends on your build.

You need diff head bolts or studs. 351's are 1/2" versus
the 7/16" for 302. Head gaskets are the same both motors,
you have several good performance choices, also depends
on alum or iron heads. Rockers, covers, etc, are the same.
You need more clearance if you're using roller / hi ratio rockers
so either take out the baffle in your 302 covers or get taller
covers, and/or thicker gasket.

Timing chain setup same. Roller lifters and hold-downs same, IF you have a factory roller 351 block. Those came in 94 & 95 light trucks. Those aren't quite as strong as the earlier blocks, but fine for hot street, still quite a bit stronger than stock 302 blocks.
For older 351's, only way to roller is with retro-fit setup, pretty $.

Same firing order as 302 HO but need 351 efi distrib out of light
truck, and you need to put on the yellow stripe Ford roller cam
steel gear. Has to be drilled/pressed, best to take to machine shop.

Front brackets and accessories from HO fit onto 351 (unless you
have older front accessory setup then you'll need the 351 bracket
for either PS & AC, or PS only).

Diff headers of course. Good motor mounts to use are 302
Mustang convertible. Lower about 1" and heavier duty.

Tranny bolts up, but your flywheel or flexplate and damper
are different balance factor. 28oz versus the 50oz for 302s.
If you get a serpentine 351 motor, you should already have
your pulleys and right damper and shouldn't need the damper
spacer for the drive pulley.

Depending on your climate and AC or not, very possibly need
a heavier duty radiator. Pep Boys or AZ heavy duty brass
MUCH cheaper than alum, and brass actually cools more
efficiently than alum. Good to use a hi flow 180 Tstat like
Mr Gasket. Water pumps interchange, but you have to use
a car timing cover if you're using a car water pump - ones on truck motors are different and the truck water pump only works on the truck timing cover, so make sure you've got both the same, either truck or car. Far as I can tell, stuff bolts on the same to either.

You know about a bigger fuel pump to go with bigger injectors.
You have to get either bigger fuel rails and use braided or
other types of hose for crossover, or if you're not going radical
on injector size and hp you can use 302 rails but you have to
lengthen crossover hoses. Get an efi hose & clamp kit from
AZ - don't use stock type clamps, the efi clamps have rolled
edges so you can tighten them up good without cutting the hose.

You have to have a 351 pan and pickup, Ford and others have them. The Ford one is stock 5 quarts, others are mostly 7 but
much more $. 5 qt is OK for moderate street. Unless you have
a 7 qt pan and are going hi rpm, stay with stock volume pump.
Saves maybe 10 hp, and a hi volume pump can suck a 5 quart
pan dry at higher rpm. 351 pan uses different pan gasket.
Otherwise, gaskets the same. Good one to use is the stock
1 piece.

Get the Ford or i.e. ARP heavy duty oil pump drive shaft.

I found a 99 Mustang bolt on hood scoop that I think/hope
will give me just enuf extra room. Other options are a cowl
hood, or there's also a 70's Mercury musclecar (forgot the model)
scoop available that's a bit taller/wider. Do a search for it.
Either scoop fits the hood lines real nice. Bolt on.

You'll likely want a cold air intake kit, I got a $40 kit off ebay that
works fine, but you'd need bigger diameter if radical motor and
real big throttle body.

If you're keeping smog, you'll have to lengthen the air tube
at the back between the heads. Cut the tube, extend with
silicone radiator hose.

Probably need custom length pushrods. Get a length checker
from i.e. Comp Cams. If you happen to use Ebock heads,
Ford makes a set for 351's w/those heads and .039 standard
compressed thick headgaskets for $40 - not sure if they're
just for pedestal rockers or both types, you'd need to verify.
__________________
Michael, yes another one of the 4,200,415.
1989 LX 357w Hatch
Lightning Block, Bullet Cam, Pro-Comp 210's (< Powered the mother ship in unison with the b-cam), GT-40 Tube, Pro-M 80mm, Lightning T/B, T5Z, 3.73's.
Foxbody5.8 is offline   Reply With Quote