Thread: 351W heads on 289

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I was thinking of putting some 351W heads on my 68-289 for some more power. Can anyone tell me if the Edelbrock RPM manafold that's on my 289 will still fit? What about the headers? Are the exhaust flangs the same?

If anyone has any pro's and cons I would appriciate it. I have a 68-289 with a mild cam (not sure the specs) and Holly 650 on an Edelbrock RPM and unknown heads with flowmaster duels. It just seems like with all of the add-on's it still doesn't have the power I would like.

Other option is just an engine swap but I like the idea of the original engine.

THanks

Yeah the RPM manifold will fit EXCEPT for the 69-70 351W heads. These heads have 2 extra intake bolt holes but with minor work that problem can be solved too.
The heads are most likely choking the engine however, that RPM intake could be too large for the cam you have in the engine and hurting your low-end torque. It's ALWAYS in your best interest to know your cam specs when you have the oppurtunity. If not, that understandable, but make it alot harder to get all the components to run in sync.

Scrap the 351W swap. That's old news and not really worth the effort. You want a low buck boost? Get yourself a set of 65-67 289 heads (most have the 54cc combustion chambers) make sure they are not the Cali heads tapped for the Thermactor crap. There's no emissions bumps to hog out in these. But for an extra $100 -$150 most machine shops will port the heads for ya if you're rebuilding them. If not, that's ok too.
At minium scrap the stock valves and put in 351W valves in the 289 heads. A popular option is to use the 1.94/1.60 SBC valves.

I have a set of fully ported '66 289 heads with SBC valves (1.94/1.60) and it flows awsome for a set of casties. Probably got $475 into the heads total. I flow tested them and if you're interested I can dig up the sheet and post the data.

For example, my brother's '70 Maverick I built the engine for we used '68 castings (63cc) that already had the humps removed and had 351W valves (1.84/1.50) installed. stock '68 302 4bbl cast iron intake and '69 Mustang manifolds (not 'log' style) I used a PAW cam that has 214/224 Duration with .472/.498 lift. It a real squrrel to drive on the street with gobs of low-end tire basting power. I'm sure with a set of headers added it'll be even nastier, but that's on hold because he's got short pockets.

Those extra bolt holes in the HP heads don't matter, just ignore them. Don't write off the 351 swap, that's the only way to go with any Ford, car or truck. Sure, you can get power from a 289, but the driveability won't be there, or reliability either.

Hi it seems that I'm a little late to tell you that the 1.94/1.60 SBC valve swap but I will tell you that I just wrapped up my swap and it was a job trying to find pushrods to fit it, an a expected but feared problem. The pushrod dilema was easily solved by our good friends from Summit, $136 & 2 days later I was ready to rock and roll. When I fired her up Man! She runs great with a Comp Cams 280 K-kit.

Trick Flow use to make any pushrod length in .010 increments for about $85-$95 per set. At least that's what it was a year ago... Got mine from Scummit. I know the feelin, I have SBC valves too.