I am planning on rebuilding a 351W with intentions of replacing the 302 currently in my '90 Bronco with it. The 351W is in a '91 Bronco that has been parked for about 2 years and ran when it was parked I have the engine ready to pull out(got dark before I could get it out). Both trucks have AOD transmissions so I have the correct flex-plate for the 351W. My initial plan is to build it from the block up.

-Bored .060 over
-Crane 444232 Cam
-Dart Iron Eagle Heads(58cc chamber and 180cc runner)
-Scat I-Beam Forged 4340 Steel Connecting Rods
-Keith Black pistons(flat tops with valve reliefs)
-30 lbs/hr. injectors
-Edelbrock Performer Truck 5.8 EFI Intake Manifold
-long tube headers
-New Cast Crankshaft
-(I'm probably forgetting something)

My main goal is to get lots of torque and at low rpms even at cost to horsepower and still hopefully get mid teens in gas mileage. The Bronco I will be swapping it into came with 4.10 gears from the factory so i will be adding a suspension lift and 35's in the future(mostly likely as soon as i get the engine in). Does the setup listed above sound like it will reach my goals? Does anyone have a guess as to what kind of numbers this setup would put out? Are there any other parts that would better suit my needs? I would like to keep decent gas mileage around 15 average(I get 13 now when I drive reasonably). Are there any stroker kits out there that would suit my needs? I searched around but most of the ones I saw were making most of their power at higher rpms which is not really what I want. I plan on using it mainly for a daily driver with some possible light off-roading in the future. This is my first build and any insight, opinions, or advice would be greatly appreciated. Thanks

-Andy

 

Hey.. stop stealing my plans and build your own motor. I have a set of Iron Eagles on order....
You'll need a tunable EFI system of course, and you can probably get away with 24lb injectors. The I-beam con rods are a waste IMO, as are the KB pistons and new crank. If the motor was running before, the crank probably needs polishing at most, and the stock rotating assembly will support over 400hp with ease.. which this combo will fall safely under. There are other cams that would generate higher TQ at the expense of some peak HP, but the penalty isn't that great, these heads will put the motor into the 325hp+ range with almost any cam.

P.S. Are you absolutely sure about the 351 and AOD, this combo was never offered from the factory as far as I know.

 

I like the 393 stroker set-ups ,personally. The 393 and 408 are both torque monster set-ups. If you go that route, you'll definately be changing your parts list. I see a potential problem with your current list- .060 over, flat top pistons, and 58cc heads are bound to make some serious CR. I haven't run the numbers, but I'm guessing you may be over optimun daily driver numbers. Have you estimated your compression ratio?

 

Why .060" overbore? If the cylinders will clean up at a smaller size it would allow you to rebore it again in the future.

393 stroker can be done for a lot less money than the 408.

 

For what you're building save your money and just have the crank and rods you've got reground.

There are stroker kits on eBay for ~$800.

 

As I suspected, running some generic figures for the unknowns, I came up with an anticipated static CR of 11.5:1. Same heads and flat-top pistons in the 393 stroker set-up would put you at about 12.6:1. 58 cc heads are for drag cars and 302s IMO. The heads you have are probably fine, although they would benefit from some porting on the exhaust side. If you want new pistons , crank, and rods, I'd just buy a budget stroker kit. You could even just buy the 3.85 stroke crank, some 302 pistons and use your old rods, if you wanted. I checked out the specs on your cam choice at Summit, and while the duration and lift are probably about what you would want for your build, Summit lists that as a flat tappet hydraulic cam, and I would suspect the 351w you intend on building is a hydraulic roller. Conanski- my Chiltons has information on AOD transmissions for both carbureated and EFI motors, so I think they must have put them on at least some models. You aren't thinking about the 351M/AOD transmission pairing which doesn't exsist, are you?

 

I ran the calculations earlier today for the CR and got almost the same thing(mine was a little higher). The stroker kits are starting to look pretty attractive. I found a budget 393 stroker kit on eBay for $679.99(item number is 170221015599). It has 30cc dish pistons that when accompanied with the 58cc Iron Eagle heads should have a CR around 9.7:1. Are there any kits that anyone would recommend over others preferably in the $700 to $800 range. Also will a new throttle body be needed or benefit the engine? (ie. BBK 61mm)? Thanks for all the help and advice.

-Andy

 

The 5.8 didn't get a roller cam until '94.

The last 351w/AOD combo I'm aware of was in the late '80s police interceptor Crown Vic, as far as I know the AOD was never offered in '87-96 trucks behind the 5.8, though it was available behind 302's.

 

My bad, thought it was earier-maybe thinking of 302's.
That would explain the info in the books, but if this is a transplant motor in the '91, all bets are off as to what year it is, so I could still be right by default. I'd check the codes or tear it apart before buying parts if it was me.