Hipo Manifolds on a 351W?
- Thread starter paulw
- Start date
Edster
Founding Member
They will bolt up to the heads and should fit the chassis as well. I have a 66 with a 302 and 351W heads and I ran a set of HI-Po manifolds for a while. I got rid of them in favor of some tri ys. So if they fit my set up they should fit yours no problem as you have a larger engine bay.
Az Pete
10 Year Member
Yeah, common sense says the Hipo's should bolt up to the 351W. I just remember reading years ago that they wouldn't fit the 351. Maybe what I saw was refering to a direct bolt up to the exhaust headpipes? Also, don't forget that the 351W block is taller, than the 302.
I've been running an old set of Hedmann Hedders for many years. Last time I spent half a weekend removing and reinstalling them, with all the scraped knuckles and curse words that involves, I vowed that next time I take them off, I'm going back to manifolds. I bought the hipo's and they've been in my sitting in my garage for quite a while now, probably waiting for an AOD install.
Of course, now I see in some parallel threads that my old stock manifolds are just as good and the Hipo's. What to do, what to do?
thanks
paulw
Torrance, CA
I've been running an old set of Hedmann Hedders for many years. Last time I spent half a weekend removing and reinstalling them, with all the scraped knuckles and curse words that involves, I vowed that next time I take them off, I'm going back to manifolds. I bought the hipo's and they've been in my sitting in my garage for quite a while now, probably waiting for an AOD install.
Of course, now I see in some parallel threads that my old stock manifolds are just as good and the Hipo's. What to do, what to do?
thanks
paulw
Torrance, CA
The strange bend I pointed out on the 351 manifold extends the bottom end farther down. HP manifolds would exit higher, creating clearance problems. With an auto trans, this would not be a big deal. If you switch from the headers to the manifolds, you'll notice a power loss between 4500 and 6000 rpm. Now you have to ask yourself, how much time do you actually spend in this power range?
Well, when Terminal Island drag strip was open in San Pedro, I would have said I spend a lot of time in the top end. But with the lack of drag strips in Los Angeles these days, I only occasionally get to go head to head against my buddie's T-bucket. That #*&^ Chevy 350 beats me every time. Of course, I'm giving him at least 1,000 lbs.
When you say clearance problems, are you talking about the firewall?
paulw
Torrance, CA
When you say clearance problems, are you talking about the firewall?
paulw
Torrance, CA
Az Pete
10 Year Member
Oddly enough, when I get into those rpm's, I normally get a punch in the right shoulder......decisions is right. Headman will not commit to their shorties fitting my combo. FPA in Wa. has several to fit but is it worth the $775 for the long tubes...........HiPo manifolds are looking better all the time. ohhhhhhh
Why do you believe that the HIPOs are better than the original 351W manifolds?
I have not seen any dyno comparisons, but the only thing I note is that the 351s are larger in diameter than the hipos. However people claim that the hipos "flow better" but is this a fact??
If you ever had them side-by-side, you'd see the 351W manifolds are basically altered HP manifolds. The odd outlet on the LH side is due to the increased height of the engine (to clear the clutch equalizer), and the RH angles down a bit more. I'd stick with 351W manifolds on a 351W, and HP manifolds on a 289/302.
