HI GUYS JUST NEED SOME INFO ON THE 455 ,IT HAS J HEADS & THE # IS 396021F .MY QUESTION IS WHAT YEAR IS IT&ARE THE HEADS GOOD ONES& ALSO DOES ANYONE KNOW AROUND WHAT HP THIS BLOCK PUTS OUT STOCK.THANK YOU

 

73-76. not the best heads. I'm gonna guess 250hp.

 

Find the VIN derivative on the side of the block. The second character of that nine-character number is the year of the block.

 

THE 455 BLOCK WITH J HEADS,IS THE BLOCK THE SAME AS THE 68-72&IS THE PROBLEM THE J HEADS?

 

I believe the style of the letter F is different. I have had a 69, 72, and a now have a 73. Joe can give you better info. He's one of the more knowlegable people on here.

 

I believe the J heads are the crappiest of all the bbo heads around. Norm would know for sure, he'll probably pop in to answer your question, then berate you for using all caps in your post.

 

Unless you want over 400 horsepower, J heads are fine.
Even if you want more than 400 horsepower, a good machinist can recommend you parts to pair with your heads and machine work to make it happen.

I said it to the kids on Oldspower as well.
All of this hype is just making people waste the better heads on 18 second quarter mile cars
and/or jacking up the price for all of us Olds lovers.

How fast do you want it?
Decide that, then find a good machinist.

 

I have a set of J heads as well. I have heard from other members on this website that they are decent until about 3500 or 4000 rpm. A BBO won't be turning that high very often.

 

unless you're me, and you have to show off at every stop light

 

Yeah I miss those days.
89 cents a gallon for gas, and the stations would mount the old used tires they had in the back for $10

Burn em to the rims,
collect pop bottles,
buy crappy tires,
repeat steps 1-3


I can't do it anymore. Have to work too hard for tire money.

 

haha...94 octane is up to $3.59 a gallon here....and my olds isn't even going yet.

 

Are you saying, Olds made crappy parts?

Not this time. Maybe someone else will be kind enough to explain it to him.

Norm

 

What he said.

Norm

 

Yes. The motor that runs the power antenna on my 1991 Delta Eighty-Eight Royale is a crappy part. Did I replace it? No. Did I unplug it? Yes. yes I did. Because it's an Olds, and I don't need a radio anyway.

 

HA! Too funny! BTDT

 

ANY factory cast Olds heads (on a 455), that have no porting, and a 215-230 hyd cam, will et better if you shift them around 4400-4600 rpm. Even F or D's. Fact of life.

With big valves, a big hyd cam, and some port work, you still won't need to rev it past 5400 rpm. The heads are the limiting factor. You need to raise the port entry as much as possible.

Although J heads are not the best, they really are not that far behind C castings once you put bigger valves in them.

JMHO