View Full Version : ? about cylinder heads on vehicle engines.

Az Gardener
02-18-2007, 02:37 PM
I have an old Chevy with what I'm pretty sure is a 454 the heads are cracked and warped. I have been to several companies in town that specialize in valve jobs, heads etc. I cannot find heads that match or look like the ones I have.

One place told me they thought the engine was a 427 I have never heard of Chevy having a 427 I am about at my wits end I need to get this truck put back together and sold it is taking up a prime parking spot at my in-laws.

Why did they make different shapes inside the heads for the same engines?

If I find one that is close to the same shape can I use it?

Is there anything to the possibility I have a Chevy 427 engine?

I have had the truck for years, the guy who sold it to me said it had a 403. When I had the flywheel replaced they said it was a 454.

Help :confused:

02-18-2007, 06:16 PM
Yes, chevy made a 427.

You need to check casting numbers.

jim dailey
02-18-2007, 07:04 PM
Yes, chevy made a 427.

You need to check casting numbers.

Chevy DID make a 427 engine. 60's into the 70's. Take the casting numbers to the local Chevy dealership, Parts Department, and they can run the numbers for you, to see what engine you have. Hope someone DID NOT make-up a bogus combination on the engine. Good luck.

02-18-2007, 10:05 PM
You could possibly have a 454, 427, 402 or even a 366 or 396 engine. What size truck is the engine in. The truck engines had taller block heights and heavier pistons. Because of the different block deck height, the heads from a 454, 427 or 396 car engine wont work, well they will, but that another topic. Pickup trucks often had the car engines. You can add 427 head to a 454 block, but they must be changed in pairs. Pull the valve cover and get the casting number on the head and take that number to the dealership to see if a new replacement is available. Also wouldnt hurt to list the casting number here, never know what someone has laying around. Who knows, you might have a set of heads worth a lot of money, well its possible, you didnt say what year your motor was. I also saw a complete 454 engine for sale on the DirtForum.com site a couple of weeks ago. Might want to check there for a set of heads. There is always someone there selling motor parts, albeit mostly racing stuff. But i wager if you post what you got and what you want at that site, someone will have it.

Dirty Water
02-18-2007, 10:07 PM
You can make just about any chevy big block head work with the right combination of a cam, pushrods and rockers :)

Az Gardener
02-18-2007, 10:23 PM
The truck is in a 1970 Chevy 2500 Custom Camper Special. It has big helper springs, I used it for years, it will carry 2-tons without squatting.

I don't think the engine is the original but I don't have a good reason why. We have the engine chained to the frame because it was always twisting and breaking motor mounts. It is powerful.

I found some numbers on the manifold behind the carb. Big initials GMT and below it 3855287

there was also B 27 70 in another spot.

and conv 3

So I am hoping one of these is the cast number?

02-19-2007, 12:27 AM
most likely it is a 402 in 1970 which would have type 2 cyl heads w approc 109 cc combustion chambers.You can find some 454 open chamber heads with 121 cc chambers cheap at the junk yard and bolt them on.You will ose a bit of compression though but on the bright side you can run lower octaine.You can mail order a set from PAW 818 678 3000 i used to work there.make sure you dont get post 1990 heads as they are a bit diffrent.Also type 1 396 heads can cause a collision between edge of dome on piston and cyl head.Sound confusing yet?Also 454 heads the exhaust springs are shorter due to valve rotators so you cannot run a cam over .450 lift on exhause side.Best to try and replace with same casting number on cyl head.

Az Gardener
02-19-2007, 01:27 AM
When I had the flywheel replaced they said it was a 454.:

The flywheel for the 402 or 3 or whatever engine I thought I had did not fit. The one that did was for a 454 Thats how we decided that is the engine I have.

Why so many different internal configurations for the heads on one size engine?

02-19-2007, 01:07 PM
did the flex plate have a weight welded on one side?Is it an automatic?What are the casting numbers on the cyl heads?you can ggogle the casting numbers and find out what block and heads you have.

Az Gardener
02-19-2007, 02:02 PM
Dealership was no help, their records only go back to 73 I was told.

Don't know about the weight on the side of the plate, it is a turbo 400 automatic transmission.

The casting numbers on the head are 3975950

How do I do a google search, or what site do I search for to enter the casting number?

Az Gardener
02-19-2007, 02:14 PM
Crap, It is a 427 according to the casting numbers. Thanks for your help.

02-19-2007, 02:15 PM
looks like original heads type 2 110 cc chambers,can be replaces with same or and 119 cc 454 heads from 73' to 89'.They are easy to find call PAW they can ship to you ask for chuck short and tell him gary sent you.ask for type 2 large ovals and get a price.or go to your local cy head shop and ask for a good set.probably run around 6 to 8 hundred bucks plus gaskets 60 bucks.

02-19-2007, 02:17 PM
no i thinks its a 402 those heads where used on more than one engine go to motec.com they have all the casting numbers there.

02-19-2007, 03:13 PM
68-70 427 BLOCK ID # HEAD ID #

340220 364776 473478 3874470 3925521
3937726 3955276 3969858 3999294 3906691
330864, 3904393, 3917219, 3933148, 3975950, 3986133, 3986136

02-19-2007, 03:17 PM
If you dont want a 427, how much payup ?

Az Gardener
02-19-2007, 06:50 PM
I was hoping to get it back together and sell it for 2700. If you want the whole truck as it sits now come and get it for 2,000. The weather is nice.

02-19-2007, 07:08 PM
Post a pic. also see if you can get the numbers off the block. Numbers should be stamped on the block, just below and in front of the right side head.