quick question on spark plug wires. I recently bought new plug wires for my bird and i am wondering what the install method is. The wires came with a sheet that listed what wire goes where but do i need that if i know all the wires on it befor are in the correct place? I am thinking all i have to do is take one wire off at a time and put on a new one. They are not plug specific correct?

Correct. The wires are just wires. The difference is the length. Use the wire closest in length to replace each stock wire.

thank you! that will for sure save me alot of time from starting over. man everyone on here has a lot of exspierence i guess b/c it seems like all my questions get answered very quickly.

Don't worry, you'll gain your experience quickly since you are doing your own work. So far, it seems you are quite confident to tackle just about everything you've posted here. That's a plus.

And one wire at a time makes it easy! If you do some how mess up just refer to the firing order and hook them up to the appropriate cylinder working around the distributor starting from a known point or cylinder...

Just wash your hands after taking off each old wire. They attract dirt big time and your new wires will look terrible afterwords.

well guys looks like i wont be doing much of that because the wires i ordered are incorrect. I ordered a set of 1973 plugs thinking that was the year my engine is because that is what i was told it was. I have tried fiquering out the year but i just cant seem to find the engine code. But long story short the wires did not fit much HEI distributer.

if any of you guys could help me out on which wires i should buy that would be appreciated.

You might try ordering a set for a 75 or 76. Or, you can get the ones that allow you to cut to lenght and get a perfect fit.

That's what I did, went to the local Napa, bought a set of AC Delco generic black wires, and cut them exactly how I wanted them. Looks much nicer that way.

You can look up the head codes to get a better idea which spark plugs you should be using.

As for the wires, the early 70s was also the time of the short-lived unitized ignition. To be sure to get HEI wires order for a 1975 or later application.

thanks for all the info, i will try and get it straightened out.

Are you positive it's a Pontiac engine? A lot of 'birds have Chevy transplants.

yes b/c it is the pontiac blue and it has 400 stamped on the side

Ok, then all the codes can be found using this resource: http://www.yearone.com/updatedsinglepages/id_info/pontiacengineid/pontengid1.html

Follow through all the "Next" links and post back here, and we'll help you identify what you have.

Chevy made a 400 and blue is just paint.

well i saw the YT stamped on the front of the block underneath the numbers 0059122 and I saw YT posted as a 1972-1974. i saw no codes that even started with 0

First, there were more years for YT engines than '72 - '74. That code was also the standard 400 block with an auto tranny for our Firebirds in '67 - '69.

2nd, the number underneath probably represent the the partial VIN stamped on the blocks starting in 1968.

You might want to try and pull the date code off your block to find out what year it really is.

see but thats the problem i cant find it. i have listed all the codes on here befor and nobody knows.

If you list the codes as displayed on that website, and tell us where they are located, we can decode them. There are no mystery numbers other than those stamped by a rebuilder, and they don't matter.

On this site, if you don't get answers, it's because the information or question wasn't clear.

on the block the code was 0059122 YT
and on the heads all there was is 1094 D N
also c is stamped on the side of the block near the bottom
this was on the manifold l064. and this was on the top part of the manifold 496140

these are all the numbers on the block i could see without taking it out of the car. I know this site is very helpful and it is rather hard to answer a question when you cannot see the problem yourself so thanks for the input everyone.

"0059122" is the partial VIN from the car that the block came out of.

YT is the block code that was used for 400's from '67-79, and again from '72-76. You still havent posted the number cast into the cylinder block back near the distributor. That would tell you what year of "YT" 400 that you have.

1094 is likely a casting date on the heads but the first digit would be a letter indicating the month. That first digit may be an "I" which would mean the casting date was September 09, 1974. Cylinder heads cast in September of 1974 woud have been used on a 1975 vehicle. Check for numbers cast into the top of the center exhaust ports on the cylinder heads. I'll bet you'll find "5C". Maybe that's the C you mentioned on the side of the "block" did you mean the head?

The "D" and the "N" woud have a pointer between them indicating whether the heads were cast on day shift or night shift.

The intake manifold was probably cast on September 6, 1974.

yes i did mean the head, sorry i am still learning. and the D N had a screw between it and was pretty rusted so i was unable to see a arrow.

and i am having a hard time finding the number cast. Is it in the arear driectly where the distrubiter goes in? or...

i am sorry but i am still on a learning curve, and when i say curve it is a pretty straight line b/c i am brand new to working cars as of this year. A gas powered R/C car is as close as i have came to working on a car since now.

If you look at the web link I gave you, it will show exactly where those numbers can be found. You need to read all the pages. Yes, the date code at the back is often hard to find because it is in an area that catches a lot of grease and dirt. So look for the block casting number, which will narrow it down to just a few years.

Then get the cylinder head codes of the center exhaust runners. That will help narrow it down too. If the heads have a number and letter, like 4C or 5C or 6X, also look for a stamped number on the leftmost vertical rib. Hard to describe, look at the pics in the article.

The intake casting number and date can be deciphered, but it is relatively meaningless. It's not a '67-'69 intake.

Most of us on this forum started working on cars before forums like this were available. You have a lot better access to information now. I had to go to the local library and order service manuals from the county library to get info like I post on my site.

im sorry guys i know this must be aggettating to all of you b/c you guys would of already found it. But i looked on the link yellowbird gave me serval times and the casting number was said to be back behind cylinder number 8 and i took mirrors and looked and looked and looked. But i have not come up with anymore numbers. Mabey it was painted over or there is a lot of dirt built up but i am having a tough time finding the codes.

The block casting number can be seen (sort of) from the top, behind #8 cylinder right by the bellhousing on the block, not the cylinder head. If the engine is as dirty as my old 400 in the photo below, you will need to use a scraper and wire brush to find the numbers. It can't be hidden by paint, it's raised above the block casting.

If it's an early engine, the block casting number will be up by the date. First pic is a '67 400. Second is a '71 400. On the '71 note its location near the oil filter adapter.

1970 400

ok after a long time i found it! 481988

so it is a 1973 400 engine, and i am still searching for what it was in...

481988 narrows it down to 71-75.

Now, go to the front, and find the partial VIN located behind the lower radiator hose alongside the timing cover. This one is hard to find. It's stamped in. From below, with a flashlight and rag to wipe the grease, is easiest.

0059122 YT

this is the only think on the front of the block i saw.

Nope. That's the engine unit number (from the Billing History of the car it came from) and the engine code, which is for a 400 4bbl. There is a partial VIN that will tell what kind of car it came out of, if you want to know that bit of trivia.

well that can wait. just so long as i know it is a 73. for when i need parts, such as i am in need of a new belt for my power steering.

But since the heads say 5c on them what does that mean?

You do NOT know that it is a '73. Only the casting date or partial VIN will tell you that.

5c are 1975 only heads.

Year Engine Hp Code Valve Misc
1975 400 ALL 5c,6s 2.11/1.66 7.6cr
1975 350 ALL 5c 2.11/1.66 7.6cr
1975 400 ALL 5cx 2.11/1.66 7.6cr


Again, that does not positively mean your engine is a '75, only that the heads are. However, in 1975 there was a 400 YT with 5c heads. sc
1975 400 185HP YT A 7.6 066 5C 1-4 7045266 Block Casting # 481988/500557


If you are buying spark plugs (which fit the heads) buy for 1975 Pontiac 400. Those should be tapered seat.

i thought the numbers i just posted were the casting code?

481988 is the block casting code. It was used on 400 engines from 1971 through 1975. All 400s, not just YT code.

YT was used 1966-1969, 1972-1976, and 1978. Just those two codes on the same block narrow it down to 1972 through 1975.

The 5c is the casting code on the heads and was only used in 1975.

The intake manifold part number and casting date are 1975 model year.

My guess would be that you have a 1975 engine. I am not sure what models used the YT in 1975, but the partial VIN can tell you what assembly plant it was installed in, which narrows it down. It was a 185HP engine, not exactly a screamer.

well i will look more for the codes in the morning.

but if it has a holley 650 carb and flowmasters on it then shouldnt it boost the HP some?

Not unless the cam was changed, and the entire engine is in good shape. A 650 is on the small side for a performance 400, though it should be fine for what you have.

Hear is the block # behind the #8 cylinder

yes thank you yellowbird and 8point for the photos. but i have already found the block number thank you

A holley 650 will give you less performance then a stock q-jet, so plan to get one.
Milage will probly be better too...if you can keep the pedal off the floor
Flow Masters should be called Flow Stoppers.
Dynomax's cost less and flow better. Sell the flow mstrs to a chevy/dodge guy.
And make sure you buy ignition wires for an "hei" distributor.
Wires for "points" are not made for that much voltage.
AC-Delco R45TSX(or equivalent brand) gapped at .060

well thanks for the info, looks like i will need to plant a tree that grows money...