302-351w question about engine changes over years

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May 4, 2007 | 05:54 AM

crzyone

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302-351w question about engine changes over years

Hello there, first post!

I am looking to put a 351W into my 1995 F-150 2wd truck which currently has a 302.

I've done searches and a lot of reading and just need a few questions answered.

I would like to know what years of 351w will work in my truck. Not exactly sure what changed over the years on the 351 besides going to roller cams in 94. I think I read that the 351 is balanced different than the 302? My truck is an auto so will my torque converter just bolt on to the 351 with no problems?

Also a question about the wiring harnesses. Do I use the 351 harness and ecm or do I take the one off my 302 and use it on the 351? All the ecu connectors are the same?

I'm used to working on gm and cadillac stuff, pretty new to working on ford trucks.

Thanks for any information, I appreciate it!

May 4, 2007 | 06:05 AM

taisa899

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From: Cookstown

Well I can answer 1 of your questions for sure. yes your torque convertor will work and bolt up without any problems

jim

May 4, 2007 | 08:21 AM

Conanski

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From: Ottawa, Ontario

You need a 351 flywheel, and whether or not you need a different computer depends upon the engine/tranny combo you have now, and if it's mass air or speed density. The mass air computer will run a 351, though not 100% perfectly, so you may need a module(chip) for it. If it's SD then you definitely need a 351 computer. Then depending upon needed computer changes, the engine wiring harness may need to be slightly modified or just left as is. For the most part though the changes are very minor, just moving a few wires around in the connector for the most part.
There are a number of engine parts that are unique to the 351, so it's highly advised to find a complete motor for the swap.

May 4, 2007 | 03:53 PM

baddad457

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From: south louisiana

For the max performance and ease of the swap, you need a 94-97 roller 351. Same cam, and heads as the 5.0 for those years. And as Conaski said, you'll need the 351 flexplate as it's balanced differently than the 302. If you have access to an engine balancer, you can rebalance the 302 flexplate to work on a 351, you just need to remove some of the counterweight.

May 4, 2007 | 04:13 PM

crzyone

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Thanks for the replies. My main question was answered, which year of 351 would be the easiest swap over. If I buy a 351 I will be sure to get all accessories and flexplate on the motor.

One more question. Will I have to modify the exhaust to work with the 351? I read the motor is slightly wider and slightly taller. Are the 351 and 302 exhaust manifolds the same?

Thanks guys, appreiate it.

May 4, 2007 | 08:58 PM

baddad457

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From: south louisiana

The exhaust manifolds are interchangeable (either will bolt onto either engine) but there were some differences between the right (passenger side) manifolds between the 302 and 351's. The 351 manifold supplied the EGR gasses to the EFI intake, the 302 sourced this off the intake, under the upper intake. The as you surmised, the 351 is taller and wider than the 302, moving the manifold outlet away from where it is on a 302. In that case, you simply need a 351 Y pipe or an exhaust shop.