Thinking about replacing my 289 heads for 351. Will my intake setup ( 4bl ) fit 351 heads? Or will have to buy a new one that matches up to the 351 heads?
Thanks

 

351 windsor, not 351 cleveland or modified.

 

and you want 69-70 heads, if you cannot find C9 or D0 casting heads, look for later model GT40's (which are a better choice anyhow)

i have early 351w heads and i love em, so i can attest to the fact that they are good heads

 

I had '69 351W heads on a 302 with a Comp Cams 270H cam, Holley 600, Edelbrock Performer intake and JBA headers and it pulled 225 RWHP on the dyno. You'll want to use the stepped head bolts for the swap.

 

^^no to be a dicck or anything but with what you have you should be turning better numbers than that

 

Not really, the 270H is a flat tappet cam, not a roller, and early windsor heads aren't that great. Better than most stock heads of the era, but c'mon, they're 35 years old. Think that most of the guys like me that are running 5.0 HO engines with roller cams(that alone can make a huge difference) VERY good aftermarket heads like AFR or TFS etc, and good intakes and making around 300rwhp? Good heads and a good roller cam with the right intake are worth about 75hp at least. 69 windsor heads blow compared to some of the stuff on the market today(like AFR, TFS, Canfield, Dart yadda yadda). Early windsor heads, or GT40 heads are a good bargain replacement head for performance, but if you want to really make power, you're gonna need a good aftermarket head, or a really good port job on stock heads by a professional(which will cost just as much as buying new aluminum heads in the end)

 

^^^ Well said.

With the plethora of aftermarket goodies available now and even minivans coming from the factory with 260hp, many may have forgotten or weren't around to know that 225 RWHP (about 300HP at the flywheel?) was a pretty spirited number out of a naturally aspirated 302. The engine was built by Racing Head Service and I got the ported and polished heads from my dad when he bought what I believe was the first available aftermarket aluminum head, the Alan Roots which later were repackaged as the SVO J302 heads.

Nowadays, you can buy some offshore knockoff heads on Ebay that will spank the 351W heads. FWIW, I got the engine in 1989. A lot has changed since then.

 

Just to clarify, I was turning 225 HP at the rear wheels, not the flywheel.

 

That's around 270 net at the flywheel, which is close to 300bhp. Rule of thumb is whp x1.2=fwhp and fwhp x0.8=rwhp. And when you think about it, the new Mustang GT's have only become 300bhp standard within the last couple of years. Nowadays with the right setup in street trim, you can get 300rwhp n/a without too much difficulty, which is around 360 net and depending on accessories, close to 400bhp