I bought my '69 back in about 2006. It was originally a 350HO car, but the guy I bought it from had a 400 freshly rebuilt and installed that. I have not cracked the engine open to verify things, but I do remember what he told me when I bought it. I'm trying to figure out the rationale that he had when this was put together. Keep in mind that the rebuild has maybe 15K on it, so I'm okay driving it as it is, but ultimately if I'm going to have the 400 in it I'd like to take it a bit further.
Currently it's (what I believe to be) a YD code 400 with a 9799914 casting number. I believe it's a 290HP from 1970. I don't know what was done to the block during the rebuild.
He installed a "hotter cam," but I don't have the specs on that.
The heads are #15, which I believe are small valves and higher compression. Date Code is L227, so made the very end of '67. They seem like a strange choice to me. I know that he had hardened valve seats installed, so it's possible that the head was machined for larger valves.
The carburetor is a Carter AFB 625cfm.
The intake manifold is an Edelbrock Performer - I believe the 2156.
The exhaust manifolds are 9777755 on the driver's side and 9799328 on the passenger side.
HEI ignition has been installed.
This is all in front of an M21 close ratio 4 speed with a 3.36 4 pinion posi rear end.
Cobbled together parts. Figure out what your real goals are, what type of budget you've got and go from there.
1968 400 Coupe, verdoro green, black vinyl top 1968 400 Convertible, verdoro green, black top 1971 Trans Am, cameo white, auto 1970 Buick Skylark Custom Convertible 350-4(driver)
Thanks guys - this all confirms what I've been thinking. If there was some kind of worthwhile plan I would probably work from there, but it looks like there wasn't.
My initial thoughts are that I'll probably replace the Carter with a QJet, look for some heads that will let it breathe a little better, and likely replace the exhaust manifolds.
I want to keep the M21 since it was original to the car, although it's likely that the rear end was originally a 3.90. I'm debating which one I'd rather switch out - I like the 3.36 on the highways but the M21 is original. They just aren't necessarily the best of friends off the line.
If I could locate the correct 350HO I would probably go back to that configuration just for originality sake, but I don't see that happening.
"...If I could locate the correct 350HO I would probably go back to that configuration just for originality sake..."
Well, you could build an engine that has the correct numbers on the heads & intake.The biggest cost item will be #48 heads. But there are a few sets still out there. Any '69 Q-jet intake will work.
There were 2 '69 Bird 350HO manual trans block codes. The WK code was also used on some '71, '72, & '73 400's. The WN code was used on some 350's in 4 later years. So, you might be able to come up with a block that has the correct code on it. Don't think you can read the block casting number in most Pontiac engine bays. So, without too terribly much added expense you could have the correct number heads, intake, & block code.
Thanks Oldskool - I've been thinking about doing that.
My ideal plan would be to find a set of the #48 heads and have those redone and installed on the 400 that's currently in the car while I look for the proper block, which I think will be even harder to find. Then at some point possibly transferring the heads. Either way it would be nice to have a correct 350HO in case I ever decide to part with the car.
Thanks Oldskool - I've been thinking about doing that.
My ideal plan would be to find a set of the #48 heads and have those redone and installed on the 400 that's currently in the car while I look for the proper block, which I think will be even harder to find. Then at some point possibly transferring the heads. Either way it would be nice to have a correct 350HO in case I ever decide to part with the car.
Riv
These are high, rusty, & will need everything. Just assume they are rebuildable.
May be able to find a better buy from someone off one of the Pontiac forums. I'll ask around & see what I can find. I sold a ready to run set a few years back, for $800. Probably worth more now.
A guy from NJ, Larry Dillon, just posted a set of core #48 heads, on the Pontiac Pickers FB page, for $600 + shipping. Says a shop told him they were good.
Well when consider that there's another $1K in parts and machine work to rebuild them and them think about how much a new set of Eheads cost I'm not sure you could get much more than that unless they just happened to be the right date code for a restorer.
I see #48 heads pop up quite a bit. Just keep an eye out if you haven't found some already. But plan on opening your wallet. You are correct that the #15 heads on your motor are a bit of an odd choice but they were 400 heads. Small valve higher compression. They make ok power but not the way most folks would go. Probably work if those are the ones you have. Of course you are correct they may have been altered and had larger valves installed etc.. Easy enough to check. They would work pretty nice on a mid-late 70s smog TA. I'm sure you can unload them easy enough especially since they don't need any work. Plug and play for next owner.
All the advice you got above is right on. Just wanted to say that i've always thought the 350HO was one the the coolest Firebirds. It really represents the factory doing what hotrodders would do. Bump the compression. Put on bigger intake and carb. Better exhaust. Burn rubber.
Seems like they should have sold a ton of those bad boys? It just wasn't a 400. That's that. You still see it today. Look at the great V6 engines in a lot of base model cars... mustang, charger, challenger, comaro. The Comaro's 3.6l V6 makes 355hp for god's sake!! And if I told you I bought one you would think I was nuts for not getting an 8!!