[bird72]

Just to clarify 71 heads and intake is what we have. I have oversize RA Ent new manifolds. In my prior aborted HO attempt the cracked factory manifold nightmare ensued and this time decided for once repro was a functionally better route. I need a crossover, have offer on repro, so doing detective work on opinion / fit / quality, it looks nice in pic. Slight appearance differences probably would not matter to me. Of course a 71 GM one would be preferred.

I looked on ebay on 71 head pics see some have all holes (?) wondering if some 197 came double drilled and some not. Or are double ones owner modded.... I lean towards drilling head as smart, but if it is of no value and degrades head I guess I would not, but really don't care in this area also as to head "virginity" too much unless drilling is just dumb move stuff value wise. But it does seem smart engineering wise to drill for grins.

['ol Pinion head]

Originally, 197's, whether early style with no dates, or the later production style cast in early Dec after the strike, only had 4 holes on the flange area to attach the exhaust manifold. I looked at heads on my '71's engines, as well as extras I have, and pics of both styles that have been on original engines that I've had in previous cars, also pics of ones Ive traded off, all only had 4 bolt holes, not 6.

In the late '80's, there was a fellow from the San Antonio area that at Tx swappers was buying up cracked roundport manifolds and I can remember him telling me, he was providing them to Delfield. Shortly there after Delfield had his version of the A-F body roundport manifolds recast. When he did, he used the later SD manifolds as the model. The SD manifolds have more attaching holes in them. From owning several 71 HO cars & quite a few pairs of 197's, what I believe you are seeing is heads that have had two bolt holes drilled and tapped so typical thin flange headers could more effectively seal. I don't see how a very rigid exhaust manifold, ESP the repro's from RARE, are not going to seal up with the right steel gaskets. Of course, several empty holes with no bolts in them is going to look odd, but some will probably see an oddity of viewing a roundport headed engine in the car. It's your choice how to remedy the problem, it's not like you are in several of our shoes and will get dinked in Concours judging at Nats for having the wrong exhaust manifolds, or get told the oversize manifolds are wrong for the car at Purestock events. just my.02.

[FrankieT/A]

When they reproduced the crossover, they reproduced the 69-71 one I'm sure is because of the year coverage. However, you can use a 72 crossover on earlier years but not vice versa. In my case the only 72 crossover I have is original to my 72 455HO Formula. The rest of my factory aluminum manifolds are Ram Air IV and when I aquired them over the years I was never able to secure the crossovers to go with them. So, what did is bought the the reproduction crossover and I mig welded the area in question and ground it smooth and finish it off with a file. Of course you can't weld to cast iron but in this case it's not structrual, the weld has enough bite to stay in place, it does burn away and is undetectable. I have over 50,000 miles with no issues.

[bird72]

thank you everyone for all the great input. OPH I agree on sealing part and will drill for basically appearance. Also agree on illogical car. I did get RARE gasket also. BTW, the big bottom angle cut flange is razor sharp on their manifolds. Not too much blood, but in the handy part of hand no band aid works Getting repro xover from member (THX) so the world keeps spinning. this is great thread, lucky.....

[bird72]

Don't any of you HO guys want to run an unpainted manifold just a little bit? Looking at my new acquisition on the workbench, I will really have to resist not painting, but I will paint no doubt. Keep picturing a patina'd aged aluminum atop the motor. I know it is a felony though. Although if anyone has a car to commit felonies on...

[RamAir]

Sometimes you just gotta say Whisky Tango Foxtrot and do it the way you like. The first owner of my 72 painted the engine metallic Blue, chrome valve covers, and unpainted intake. Looks awesome and doesn't bother me a bit.

[Brewster]

Pic Pic

[tahosdra]

seems like they were on a budget compared to 69 and 70 my 70 has chrome rocker covers nicer wire retainers etc so I did my 72 proper engine color bare intake chrome rocker covers 69 70 wire retainers looks like how it should have
been imo

[njsteve]

Anyone have a spare set of those dreaded chrome valve covers that we all hate seeing on 1971-2 455HOs?

I'd love to put a pair on the 455 my son and I are building for Gramma's '75 Firebird. (I have a generic set but both covers have large breather holes instead of one with an oil cap hole).

Here's today's update: http://forums.maxperformanceinc.com/...=gramma&page=9

[Formulabruce]

Originally Posted by njsteve

Anyone have a spare set of those dreaded chrome valve covers that we all hate seeing on 1971-2 455HOs?

I'd love to put a pair on the 455 my son and I are building for Gramma's '75 Firebird. (I have a generic set but both covers have large breather holes instead of one with an oil cap hole).

Here's today's update: http://forums.maxperformanceinc.com/...=gramma&page=9

Ames has em , have used a couple pair and they are pretty nice
FN 651 $99.00

[njsteve]

I thought maybe someone has a used pair they want take off their 455HO. I'd be happy to do my part to save them any further ridicule. ;-)

[bird72]

I am looking for a nice Patina'd used set of chrome that are still nice / decent with the aging old engine chrome gets since this topic is up.

[4birds]

Originally Posted by bird72

Don't any of you HO guys want to run an unpainted manifold just a little bit? Looking at my new acquisition on the workbench, I will really have to resist not painting, but I will paint no doubt. Keep picturing a patina'd aged aluminum atop the motor. I know it is a felony though. Although if anyone has a car to commit felonies on...

Been there, done that. I had a bare aluminum intake on mine for 30 years! And chrome stuff everywhere too. What was I thinking? Well, that was then, this is now. I put it back a lot closer to the way it came, although there are MANY things that are still not 100% correct and probably never will be. That's OK, because I am happy with it the way it is.

The thing is, it's your car, and you can do whatever makes YOU happy with it. Go bare with the HO intake, and if you don't like it after a while, paint it.

Its the journey and stories with these cars that make it fun. Enjoy it the way YOU want it.

[njsteve]

Originally Posted by bird72

I am looking for a nice Patina'd used set of chrome that are still nice / decent with the aging old engine chrome gets since this topic is up.

If you dont mind breather holes instead of one breather and one oil cap, mine would work for you.

[tahosdra]

455 ho 69 70 style

[1971455HO]

I like it...I've always liked it like that. I put mine back with painted covers, but I like the chrome the best.

[rexs73gto]

I'm a bit confused, didn't the 71 455HO come with a bare alum. intake from the factory?? I had a friend who had one that he bought with only 11000 miles on it & it had a bare intake . He bought it off a dealers lot.

[Judge273]

The 71 455HO was the first roundport to have the entire engine painted the new robins egg blue. Also first roundport to make Ram Air an option.

Confused a few people and dealers. Hence, you some with the chrome valve cover, bare aluminum intakes, and added Ram Air...

[The Boss]

Supposed to be painted, but oddities seem to come up.

[Brewster]

Cool car and wanted to know if anyone here owns it or knows about it?

http://seattle.craigslist.org/see/cto/5178330124.html