454 Blocks

[1973c10]

Hay all


What year did Chevy change the block design
I am building a new motor and have a set of heads
from 74 that I want to use ( ok stop laughing )
I am going to look at a motor for a donor block
that the guy doesn't know what year it is or what
it came out of ?? I asked him for the casting numbers
but he said he didn't know where it look
and I cant tell be the picture he has
And I don't want to drive 2 hours each way
only to find out the heads wont work

Thanks much

 

[crazy4offroad]

I wouldn't laugh at all I've always from the beginning wanted to run a bigblock so it would be nice to have a place to refer back to. Subbed.

 

[1973c10]

It just funny a lot of people laugh at me
when I want to run old school heads
they say use them as boat anchors
I just say run what you have or can afford ,
I would rather have a good running BB with old heads
then have it sitting on a stand waiting for
a set of heads someone else likes

Just my .02 LOL

 

[crazy4offroad]

I know there's peanut port and square port heads for 454 but not sure about compatibility, hoping someone chimes in for you. I think the peanut ports are the ones you don't want, too restrictive.

 

[1973c10]

I have a couple sets
I just want make sure that will fit

 

[74propu]

I have a couple sets
I just want make sure that will fit

i9f you go to my pics I had a big block in my 74 it was out of a 89 burb as long as it is a mark 3 block any head from any mark 3 will work and thay started in the mid 60s in 90 chevy went to the gen 4 eng with out a fuel pump boss or a clutch z bar pivet boss but the good news is the heads off the gen 4 will work on the mark 3 block the gen 4 is known as the Tonawanda engs if and this is a big if you can find a set od 366 Tonawanda heads thay are grate heads breath very good big valve low cc hi torque hint hint school bus dump truck good luck with the bb

 

[1973c10]

so 90 and newer are gen 4 or just the ones
with out a fuel pump boss or a clutch z bar pivet boss ??
I had a 454 out of a 1992 motor home that an mechanical fuel pump

 

[74propu]

so 90 and newer are gen 4 or just the ones
with out a fuel pump boss or a clutch z bar pivet boss ??
I had a 454 out of a 1992 motor home that an mechanical fuel pump

mark 3 blocks had mechanical fuel pump and z bar boss. gen 4 did not . gm ran the mark 3 that was in inventory out in things like R/V's . just like they did with the c 30 and suburban when they changed body style in 87 used the square body till 91 in these trucks. so your 92 R/V 454 could have had a mark 3 in it

 

[HotRodPC]

I'm also aware of a 94 Class A RV that had a Mark 3 454 in it. Some of these older RV's are good to get the powertrain out of, if you're looking for things like a Th400 with straight cut planetary gears which are very strong, and many of them also had Gear Vendors in them. We all know Gear Vendors cost about $2500K. Many times you can buy an old RV in rough cosmetic condition and leaking like hell for about about $2000 and most are low mileage as far as the powertrain goes, like 60,000 - 80,000 miles because people couldn't afford to drive the 4-6 mpg units.

 

[1973c10]

Thank you so much !!

 

[85c10owner]

Actually they are Mark 4 blocks. Then GEN 5 and GEN 6. The block you need to use your old heads is 70-91. Those are mark IV blocks. Now I dont know if the blocks on the later end of that will have the clutch ball mount or not. The fuel pump boss should be there, may not be drilled on the later blocks but any machine shop will be able to drill it.

As far as the heads go, there are large oval port heads, then peanut port (smog heads but make super strong torque) and the square ports. 1974 heads will still be the large ovals, probably 781 or 049 heads. The peanuts didnt come around until I want to say early 80`s.

 

[1973c10]

Hey all

Does anyone know how to Decode this number
it is the one on the front pad
T6F724927

Thanks

 

[85c10owner]

Hey all

Does anyone know how to Decode this number
it is the one on the front pad
T6F724927

Thanks

Double check that number. Should be a 3 letters for the first 3 stamps.

 

[1973c10]

That's what I thought and have look at it 3 times LOL
I will try to get a pic of it

 

[1973c10]

Here is a pic