I’ve been looking around these forums for some info but haven’t found much, maybe I’m doing it wrong but, I have a 69 bird that came with a 400 but now has a 69 350. Tomorrow I am going to look at a “untouched” 74 455 for $750, I’ll read on the plugs and do a look over and hopefully buy it. To me it’s a good deal but am somewhat concerned how cheap it is. Has anyone swapped a 455 into a 69 bird? If so what issues did you run into? From what I’ve read, all Pontiac blocks, big and small blocks, use the same mounts?
I’ll be using my current Muncie with the 455.
If I get the 455 in and all is good, what could I sell my 69 350 for? I do know the rear main seal is going out and I have the small chamber 47 heads.
I’ve got a 455 going into mine this winter. No big and small blocks. All Pontiac blocks are the same size. The engine weight might be a few pounds more but it’s negligible. Should be no issues. Everything bolts up the same.
IMHO, you'll be lucky to get $100 for a 350 or 326 non-HO engine. The accessories (brackets, timing cover, oil pan, etc.) are worth more than the engine. I tried sell my Lemans 326 long block for $100, no takers, went to scrap.
It's a shame the 326 gets no love, back in the 70's, during high school, my buddy Rick owned a 67 FB, 326/3 speed, I'm guessing a 3:08 or numerically lower gear, chrome reverse wheels with N 50 15's, my other friend had a stock 1970 GTO, 78 series tires, 400 WT, 4 speed, 390 open rear. They decided to race one afternoon, right after school, on Hwy 54 S, right in front of the Ramada Inn. They were side by side both doing about 45 mph and took off, I was 15 and riding shot gun in the GTO. The goat had the bird by a car or two up to about 100 -110 mph, then the bird came around us and was gone. I still can't believe it! I see Butler sells a stroker kit for the 326, I think it'd be neat to build one.
Why scrap a perfectly good 350? If it is the at 69 block it has different, more solid build than a 74 smog era block. As mentioned, a pontiac block is a pontiac block, the 455's have a different sized crank journal than a 400. Depending on who you talk to, punching out a 400 or 350 to a larger size is preferable, as you are keeping more iron around the crank. More iron, more RPM. I am far from an expert, but my 400 block has been in engine jail for 3 years (getting tired of waiting on it). It'll come back as a 462. .035 over with a 4.25" stroke. I pick up any 60's pontiac block I see if it is in good shape. Posted a while ago about a cool one I found with factory 4 bolt main's that was in a Bonneville. Great find if I really want to build a monster.
If I were in your shoes, I'd pull the 350, strip it down to the block, have it machined and cleaned, and build it fresh. You've got the sweet sweet 4 speed, so putting a nice cam in it and some high flow heads will really wake it up (it's not that simple, but it a little research turns up a lot of info).
Hokie... I'd have bought that 326 all day. Those things will rev forever after a good rebuilt. I have a C-20 with a 327 that runs to 7000 rpm after a relatively inexpensive rebuilt.
The other thing good about a 455 is they all have the 5 motor mount holes so they will work with 69 and earlier and 70 and later mounts. With the later 400 blocks, you might only have the 3 holes and you can't easily install in an FGF that needs the other 2 holes.
The answer to all things is "yes". The 455 should be a pretty easy swap. Whether or not it runs, or runs well, is a totally different animal. As for the 350 it has tons of potential. Especially if someone has a 70's era bird with a smogger in it. Those 47 heads would freshen any 70's 350 nicely. Either way i would wait until that 455 is up and running before you move it.
Thank you all for the great info, defiantly appreciated!
I got the 455 the other day and, it barely turns 90 degrees then stops. I pulled the plugs and cylinders 2 & 4 had rust on the plugs so I'm soaking all the cylinders with MMO and wd40. Hoping it comes around! I didn't get a chance to pull the heads yet but, the casting on them says "5" and that it, i can't find any info out there that in '74 they used a "5" casting number, the secondary casting is 16, any ideas on what heads these may be? I'll get pics soon.
My plans for the 455 is to at least get it up and running and run it for a few years until i can afford to have it gone through and put some better parts into it.
I am definitely going to keep the 350 around until i know for sure the 455 is a runner, good idea unconn86hgiv!
It's worth the money just for the block & crank. Only issue you may have is having the correct engine mounts locations on the block, there are adapter plates that solve that problem. Listen to engine run, if seems fine, clean it up & put it in! If and/or when it goes belly up, perfect bottom end to build. Lots of quality parts out there now, can build a nice stout 455 for not a ton of money. You might get lucky & have it run strong for a good time. Buy it!