300 engine build
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Junior User
Joined: Nov 2012
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From: Raleigh N.C.
300 engine build
hey guys!!
so shortly i will pull my 4.9 out to rebuild it since i'm blue smoking. Its in an 86 f150 4x4. I've already put an offenhauser intake with a holly 390 cfm and headman headers on the truck (someone got leadfoot after this and ran the truck a little hard
) With the engine build i want to get the most power possible and keep duribility in mind. At this point for upgrades i'm looking at a cam, roller rockers, and 240 heads. any more recommendations to get more power out of this engine?
so shortly i will pull my 4.9 out to rebuild it since i'm blue smoking. Its in an 86 f150 4x4. I've already put an offenhauser intake with a holly 390 cfm and headman headers on the truck (someone got leadfoot after this and ran the truck a little hard
) With the engine build i want to get the most power possible and keep duribility in mind. At this point for upgrades i'm looking at a cam, roller rockers, and 240 heads. any more recommendations to get more power out of this engine?
Senior User
Joined: Jun 2012
Posts: 179
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From my research and no actual experience a freshly rebuilt 300 with a Offy dp, Holley 390, roller rockers, 9-1 cr, longtube header, good exhaust, and an isky mile a more cam are good for 225hp and 300ft lbs of torque. Fordsix.com the guys over there can tell you more then me
Postmaster
Joined: Mar 2005
Posts: 2,949
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From: Earth
There's no real performance advantage from roller rockers but they're probably the spiffiest looking $250 you can put underneath a valve cover.
And to that end, without the need for studs onto which rockers are fitted there's no real advantage to a 240 head if you're going to rebuild the bottom end anyway. You can raise compression with the piston (taller compression height or smaller dish/flat top) or by having the block decked.
Then use the $400 you would have spent on roller rockers and a 240 head to have some porting and a 3-angle valve job done on the head you've got now. Outside of the stock intake/exhaust manifolds the head is the single biggest limiting factor on a 300.
Otherwise some ARP rod bolts are cheap insurance. Spend a little extra to have the rods and pistons balanced, too. And find a machine shop you trust to do all the work.
And to that end, without the need for studs onto which rockers are fitted there's no real advantage to a 240 head if you're going to rebuild the bottom end anyway. You can raise compression with the piston (taller compression height or smaller dish/flat top) or by having the block decked.
Then use the $400 you would have spent on roller rockers and a 240 head to have some porting and a 3-angle valve job done on the head you've got now. Outside of the stock intake/exhaust manifolds the head is the single biggest limiting factor on a 300.
Otherwise some ARP rod bolts are cheap insurance. Spend a little extra to have the rods and pistons balanced, too. And find a machine shop you trust to do all the work.
Lead Driver
Joined: Mar 2008
Posts: 7,192
Likes: 384
From: Near Los Angeles
"...and 240 heads..."
All my research shows you'll only need one. Couldn't resist that.
I agree with BVA. But...you can pick up an inexpensive set of used bbc rockers on ebay for about $100, if you have stud type head. The ARP studs for a sbc work, and cost about $55.
Porting will make all the mods work better. Upgrade your ignition too.
All my research shows you'll only need one. Couldn't resist that.
I agree with BVA. But...you can pick up an inexpensive set of used bbc rockers on ebay for about $100, if you have stud type head. The ARP studs for a sbc work, and cost about $55.
Porting will make all the mods work better. Upgrade your ignition too.
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