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Discussion Starter #1
Well,,,,,,Now i can't make up my mind...I was set to build my boat motor 302 into a 347....I have the heads,,cam,,,,intake...Specs....heads:54cc 289...1.84///1.54,,,ported...cam [email protected] 512 lift 109 lobe..Ford motor sport rpm intake....All this will fit my 302 to 347 BUT......393 is looken good now...I could build the short block for less money than the 347 and have a stronger engine.....Will my cam and heads work on the 393???? OH and my 302 flywheel....I know my intake will not fit the 393......I only want 400 to 425hp and run on pump gas...The 393 will do that with ease.....Any help would be appreciated......Russ.......
 

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393!!!!!! No doubt about it.
 

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Ask any honest woman and she'll say bigger is better so the 392 is a great choice. You probably won't need to spin it over 5000RPMs to get 400-425 HP but your intake won't work and your heads will need head bolt holes drilled out to 1/2".
 

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Discussion Starter #5
392 393 396 what ever you call it, sounds to good to be true....Shame my intake won't work...Had it polished,,looks real nice
very shinny...I'm going to measure the engine bay to see if i have the room for the 351..think i need about 1&1/16" on each side to make up for the wider engine.....I asked a few ladies and they told me " it's not the size that counts it's how you use it " I like to use MINE in a boat......Russ...









i:p

<font size=-1>[ This Message was edited by: Russ on 12/30/01 4:00am ]</font>
 

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Discussion Starter #6
I was thinking,,,I do that every now and then...If i use my 289 heads on a 393, how are the windsor intake runners going to match the runners in the 289 heads??? The 351 intake runners are wider than the 289....Russ.....UUHH,,,,,I was thinking again, what power difference between the 347 and 393 (torque/hp)My same heads,cam,600cfm carb...I know it's small but i have it and i'm only going to turn 5000 to 5800rpm..and RPM intakes on both...lets say 9.5:1 cr. Russ.....

<font size=-1>[ This Message was edited by: Russ on 12/30/01 10:40pm ]</font>
 

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If your 289 heads are ported like you said in above post, a 351W intake should have no problem being the right size port or even smaller than you heads if they truely are ported. I would suggest a set of '69-'74 351W heads for the larger intake ports than 289 as cast and already have the larger 1.54/1.84" valves stock. The chamber design on the 351W heads are much better for the larger valves whereas the 289 chambers shroud the larger valves too much unless a decent amount of chamber work has been done to unshroud. The 392 won't hardly be stressed at all and live a long time but a 347 at sustained RPMs like you're talking about in a boat may cause a reliability issue. 331 would be better than a 347 but the 392 would definitely be best.
 

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Discussion Starter #9
Thanks for reply.....I have a set of 351w heads '75 but they have small valves 1.78/1.45. The 289 heads were gasket matched and mate up to the motor sport intake perfect....wish i had done the 351 heads now, but at the time i was looken for higher C.R. and those small chambers on the 289 heads did the job.....seems you can never get enough power.......Russ..... P.S. If i had a endless supply of money this would not be a problem......

<font size=-1>[ This Message was edited by: Russ on 1/2/02 9:39am ]</font>
 

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'75 and '76 351W heads are the same as '74-'69 except for the smaller 302 valves. They will take the 1.84/1.54" or 1.94/1.625-1.65" valves with no problem and don't have the shrouding associated with 289 chambers while having the bigger intake ports. It will cost you money to have your 289 heads drilled out for the larger 1/2" 351 head bolts and you may want to have the valves put in your '75 351W heads instead.
 

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Discussion Starter #11
I think drilling out the 289 heads would be a cheaper route,,maybe not the best.....351 heads would need guides and port work....I could run the 289 heads for a season and do the 351 heads later:roll: Can i drill the heads out myself on a drill press??? Russ...
 
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