Pontiacs say what they are on the side of the block usually. A 455 will have 455 cast onto the side of the block as will a 400. Also most blocks have the displacement and other information stamped onto the front of the block where its machined above the timing cover. Otherwise except for the 301 all modern Pontiacs look alike from the outside, there are no "big block" Pontiacs.

 

Due to the bad weather I’ve not been able to do much with my truck apart from ordering tat from eBay, but this last week although it’s still cold , it has been significantly dryer, it’s the break I’ve been waiting for and , I have now been able to look for the casting marks but, I am no closer to identifying my engine, I have F237 cast on the rear rhs. SX on the LHS manifold, 500555 cast into the rear of the block by the distributor. 1N on the front LHS of the block and GM3 below it. I have tried to google it but it just seems to send me round in circles. I’ve bought two Pontiac firebird manual’s both chilton publications , early and late editions and hoped to use these for a source but I can’t find anything. Hopefully someone will be able to point me in the right direction. Thanks in advance 👍

 

It should say right on the side of the block
350 or 400 or 455 numbers cast in block
If an old 326, I am not sure if those are cast in the block

 

Hello, Thank you for the reply, I have looked everywhere with my torch but cannot find any other markings on it, the drivers side is tight up against a wall and I am struggling to see any further information on this side. My drive is sloped and as my truck is not running, there’s not much access available to me. Also the rear wheels are off as I’m waiting for rear brake shoes to arrive which isn’t helping me . I am trying to think ahead with everything I do because the parts take such a long time to arrive from America ,typically four to five weeks. Also it’s not the cost of the parts that are expensive but the postage, it’s absolutely ridiculous. A $56 rear window costs $333 to ship to the UK , then I have to pay import taxes of 20% on the the part and the postage of the nearly $400 transaction. So $480 for a $56 part . Hopefully I don’t think I’ve much more to buy for it that I can’t source in the uk apart from a pair of inner wings that are missing, I should be okay 👍

 

heres a site that may help you a tad more ,
https://www.hagerty.com/media/mainte...20model%20year.

with this section reading

(As you look there you may find a pretty simple clue that will end your engine identifying search. On 1968–69 428 blocks you will find “428” stamped between the freeze plugs. On blocks produced in 1970 and after, you will find 350, 400, or 455 stamped towards the left side of the front of the block. There is no displacement stamp for 421, 389 or 326 blocks.)

 

also in this site along the left side is a engine part code listing you will find a section that reads [url alt="Info on
Pontiac Engine codes"=http://www.wallaceracing.com/engine1.htm]Pontiac Engine Codes[/url] and a Wallace Racing's Pontiac Engine Search where you will find a very detailed photo and text showing where to look

 

I would like to thank everyone for pointing me in the right direction, because of this I have managed to ascertain that it is in fact a Pontiac trans am 6.6 L 400 engine. Also the running gear is also a Pontiac trans am 1975 to 1977 . The gearbox is a General Motors th400. From the information that I have gathered about the Pontiac 400 engine , it may not be in it long 🤬👀. I tell you something at my next reincarnation I’m getting in a different queue ! 😊

 

nothing wrong with a poncho. they were a long strong motor , t400 while old is still used in drag racing, i'd drive it till it dies.

 

Thanks for the support Charlie, I bought my truck as a rolling project from the family of the deceased owner . Loads of parts were missing from it and considering that I only started working on it early February, I am pleased with the progress. I have not had it running yet and can only cross my fingers that it will actually run at all ? At the moment I am finishing the re wiring in the cab, once this is done my list is getting shorter and I think in another week. I will hopefully be attempting to start it 🤞it’s missing the inner wings/fenders that I’ve been unable to attain so, I’ve bought some metal to hopefully fabricate some new ones with. A fellow web member Mike has offered to take some pictures of his for me , to show me what they should look like . Such a kind gesture to take some time out of his life for a stranger is very humbling 👍 I am a keen motorcyclist and have a few classic bikes so ,I do like to join websites to further my knowledge and passions but, I have to say this particular website is without question the friendliest and best I have ever come across. I will let you know when I fire it up if it’s a dog or a keeper 🍻

 

good luck with the truck,should be a eye catcher over in the UK with a Pontiac for power,

 

What classic bikes?
Post photos of those
Pretty neat motor in the 51, I'd keep it in there, at least until you burn the TH400 up
That 6.6 should be fairly fun to drive, the old TA's sure were

 

Cheers Charlie, Almost finished the rewiring today, hopefully I will have it running before the weekend comes . Vehicles over 40 years old are tax and mot exempt in the uk , also the insurance is cheaper because it is a classic vehicle so once it’s running technically it will be on the road 😎🍻. The Ford f1 51/52 has been my dream machine ever since I was a boy . I love American cars / hot rods and the car culture but this particular truck with its grill is just Wow ! I plan to put a car port along side my garage when it’s finished as currently it has two rain covers over it , I lift the cover back just to work on specific things but today , it was really windy and the covers blew off. As I went back to replace them again my heart just skipped a beat. Never in my life did I ever think that I would own one ! And to see it nearing completion today just blew me away 🤩 I feel so lucky owning it . I think the only drawback will be the fuel consumption, it’s currently approximately £1.20 a litre so £6.00 a gallon , sometimes it can be as high as £7.00 a gallon For 8 to 12 mpg if I’m lucky ? The most annoying thing is 55% of that £6.00/£7.00 goes on taxes ? I will let you know when it’s running and also post some pictures when it’s finished to hopefully inspire others to finish theirs . Thanks for your support Charlie 👍

 

Hello , I have a few current and classic motorcycles, some I use but others are purely investments. Harley Davidson heritage softail , Harley Davidson dyna street bob, Honda vfr1200dct , Yamaha r1 50th anniversary Kenny Roberts, Suzuki ts185 1974. Suzuki gsxr750 slabside 1985 , Suzuki gsxr750 slabside 1986. Triumph trident t150 with the ogle tank uk spec. I have three Velocette vogues that are very rare bikes, only 261 made . Yamaha yg80 Yamaha fs1e dx . I have four series three Lambrettas two sx and one li and a silver special , I have bought and restored many Lambrettas over the years ,they have a huge following in the uk and we like to go on the rally’s. I have a very rare Vespa 125 , Aprilia rs125 full power 2t last of the line with very low mileage, Honda vtr1000 . I will post some pictures when I get chance, my truck is taking every spare minute I have right now and we’ve had a surprisingly warm last couple of weeks so I have been out enjoying my motorbikes in between. Do you ride motorcycles?