302 rebuild or ditch
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Senior User
Joined: Sep 2002
Posts: 110
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From: Calgary Alberta
302 rebuild or ditch
I have a 1970 f100 with a 302, 3 speed coulmn shifter. I am looking into rebuilding an engine for my truck, and I am looking to go for about 350 hp, with the potential to supercharge (later) up to aroud 500 or better horsepower. I am trying to find out how stout the block and crank is on the 70 302. how much power and rpm can the stock block and crank handle?
I am thinking if the 302 cant take what I want to throw at it I will replace it with a 360 FE with a good port job on the stock heads an edelbrock preformer rpm intake and a 750 speed demon carb, and a (roughly) 224/236 duration cam (hydraulic roller)
I am thinking if the 302 cant take what I want to throw at it I will replace it with a 360 FE with a good port job on the stock heads an edelbrock preformer rpm intake and a 750 speed demon carb, and a (roughly) 224/236 duration cam (hydraulic roller)
Elder User
Joined: Mar 2004
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The modern 5.0's take that much power and more, including supercharging, all the time, with no problem at all. The 70 block and crank is actually slightly heavier than the more modern 302's, so it should handle that much power with aplomb. The stock 302 will take 6250 rpms very safely. ARP bolts with improve the safty margin quite a bit. More than 7,000 rpm's, is routinely done with after market H beam rods on 302's.
For 350 HP on a 302 you will need aftermarket heads. This is a must, as stock 302 heads, unless they are very heavily ported, won't do that level of power. You will also need the usual performance items, such as headers, and 4bl carb, and aluminum intake.... A cam with about .500-lift and a duration of about 220-225* at .050 will do nicely.
If the aftermarket 302 heads are too expensive, then it may cost less to do the 390 with ported cast iron heads, as you will not need more than 1 hP per cubic inch, as is the case with a 302. Edelbrock makes great aluminum heads for the FE motors, BTW.
For 350 HP on a 302 you will need aftermarket heads. This is a must, as stock 302 heads, unless they are very heavily ported, won't do that level of power. You will also need the usual performance items, such as headers, and 4bl carb, and aluminum intake.... A cam with about .500-lift and a duration of about 220-225* at .050 will do nicely.
If the aftermarket 302 heads are too expensive, then it may cost less to do the 390 with ported cast iron heads, as you will not need more than 1 hP per cubic inch, as is the case with a 302. Edelbrock makes great aluminum heads for the FE motors, BTW.
New User
Joined: Feb 2004
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Just to add my $0.02 worth. The 302/5.0 is an rpm motor, basically no matter what you do it makes its power up high. An FE360/390 builds its power at lower rpm. So it is more what tire size, the final gearing and the transmission you are going to run. Probably cheaper/easier to get 350 hp with cam, manifold and carb in/on a 390 than to get the same from a 302.
Our F-whatevers are not light to go fast you first have to get them moving nothing does that like cubic inches!
1990 F150 XLT SB, 5.0/AOD, 4x4 mileage 18.6
1976 F150 SB, 360/4MT, 4x4, get up and go, priceless
Our F-whatevers are not light to go fast you first have to get them moving nothing does that like cubic inches!
1990 F150 XLT SB, 5.0/AOD, 4x4 mileage 18.6
1976 F150 SB, 360/4MT, 4x4, get up and go, priceless
