how much hp

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Feb 4, 2002 | 04:38 PM

CRJ900

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From: virginia beach

how much hp

I have a 68 360cid 2wd f100. The truck is restored all the way around from the tires 31x15x10.5 bridgestones to the whole body witha new paintjob. The engine has about 190,000 on it. I am going to get someone to rebuild it into a 390. Right now my 360 isnt too bad but the bearings rattle at about 35 and up. Right now with my truck i can get to 60 in about 9 seconds. What can i expect to get when i rebuild my 360 into a 390. What are the bestways to increase horsepower, while building my 360 into a 390. What are you all opinions about a 0-60 time with my new 390 would be?? Your opinion is greatly appreciated.
Thanks

oh yea its a auto

Feb 4, 2002 | 09:04 PM

Ratsmoker

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From: Missouri

how much hp

you will not really gain HP by throwing in a 390 crank, rods and pistons but it will feel like it because you gain a good bit of torque. IF you are going with a stock low budget rebuild get some good headers, 390GT intake or edel RPM if you can afford it, about 9.5:1 pistons and a good healthy cam with around a .550 lift and no more than around a 225 duration. If you want to dump some money check out my page. http://ratsmoker.clubfte.com

Feb 5, 2002 | 12:40 AM

FEina52F1

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From: Oztralia

how much hp

hey Rats

could ya run a 360 and 390 thru desk dyno, i'd like to see what the graffs look like

Feb 5, 2002 | 01:43 AM

Ratsmoker

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From: Missouri

how much hp

Sure, I used a 600cfm 4bbl with flow specs from a CJ head and brought the valve size back down to stock 390. Compression is 9.5:1. Stock manifolds and stock cam. http://www.clubfte.com/users/ratsmoker/360vs390.jpg

Feb 5, 2002 | 10:06 AM

karlsd

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From: Collierville, TN

how much hp

I think your numbers are a little high, mainly due to the compression ratio. My recollection is that in the late 60s and early 70s the 360 was 8.4:1 and the truck 390 was 8.6:1. With a stock 2 bbl carb and intake, that would probably get your gross HP numbers down to the 215 and 255 that Ford published.

The bottom line is that with no other changes, the 390 rotating assembly adds roughly 10% more torque and 5% more HP from idle to 3000 rpm. As you would expect, the shorter stroke motor does slightly better at higher rpms, but who runs a 360 over 4000 rpm?

The 390 also offers a lot more potential than the 360 because of the greater displacement and higher potential compression ratios. If you are going to put a lot of money into warming up your FE (any performance rebuild will run at least $1500), $300 for a 390 crank and rods is the best bang for the buck you'll find.

Feb 5, 2002 | 07:21 PM

CRJ900

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From: virginia beach

how much hp

Hey, ratsmoker. what are your 0-60 times and 1/4 mile times

Feb 5, 2002 | 09:33 PM

Ratsmoker

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From: Missouri

how much hp

Hopefully I will let you know after Sunday. My buddy has a 14.8 second subaru and I obliterated him on the street. We took off at 20 - 25mph and stopped about 80. I'm sure his 60 ft time of 2.2 is better than mine will be until I get gears and slicks. Sometimes I have traction problems at even 25mph with what I have going back there now. All the HP in the world doesn't mean anything unless you can put it to the ground I guess.