Help with my 400 build

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Joined
Jul 26, 2014
Posts
41
Reaction score
1
Location
La
First Name
Steve
Truck Year
1978
Truck Model
c20 scotsdale
Engine Size
hopped up L31 waiting for a hot 400
I get 17.5 regularly. But I rock a qjet

Thats great! I was hoping for 10-13 maybe better but I did not get this truck for mpgs
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,125
Reaction score
24,021
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
The engine I got them from had a vortec box and a l31 casting number so I dont see why your trying to say its not a vortec i made sure the engine was an l31 before pulling the heads. they are not a normal gm casting like the heads i had on my 400 they are a center bolt pattern on the valve covers. Im not gunna give up on an engine you didnt put money in. My weiland vortec 6700rpm manifold fits them too so i guess im crazy:whymewhyme: but your right I think i was wrong on the year i pulled them 2 months ago on a half off day at my local yard.

Yes, the year makes a big difference. You said '93 and vortec heads were not used until '96. Besides that, I also brought it up because a lot of people think they have vortec heads because of the centerbolt style valve covers. But centerbolt covers were used starting in '87.
 
Joined
Jul 26, 2014
Posts
41
Reaction score
1
Location
La
First Name
Steve
Truck Year
1978
Truck Model
c20 scotsdale
Engine Size
hopped up L31 waiting for a hot 400
Yes, the year makes a big difference. You said '93 and vortec heads were not used until '96. Besides that, I also brought it up because a lot of people think they have vortec heads because of the centerbolt style valve covers. But centerbolt covers were used starting in '87.

Yes I was wrong on the year but those heads are for sure vortecs off an l31. That was my bad. Thanks for looking out
 

350runner

Full Access Member
Joined
Feb 9, 2013
Posts
2,858
Reaction score
224
Location
tx
First Name
Ceasar
Truck Year
82
Truck Model
c10
Engine Size
350
Just have to ask... what's the last three #s under the valve covers between the rockers?
 
Joined
Jul 26, 2014
Posts
41
Reaction score
1
Location
La
First Name
Steve
Truck Year
1978
Truck Model
c20 scotsdale
Engine Size
hopped up L31 waiting for a hot 400
Just have to ask... what's the last three #s under the valve covers between the rockers?

On the heads in my garage? I can get the # for you and im not even using those heads on my 400 anymore, but I can assure since i was the one who took them off that they came off of an l31 vortec engine with the stupid vortec intake box i hit the box and destroyed it with my breaker bar while i was at the yard because i hate those thingss..

And the number was covered by a lot of old gunk but i believe the last three digits were 906
 
Last edited:

350runner

Full Access Member
Joined
Feb 9, 2013
Posts
2,858
Reaction score
224
Location
tx
First Name
Ceasar
Truck Year
82
Truck Model
c10
Engine Size
350
Yea those are the less prone to crack ones... so afr it is then?
 
Joined
Jul 26, 2014
Posts
41
Reaction score
1
Location
La
First Name
Steve
Truck Year
1978
Truck Model
c20 scotsdale
Engine Size
hopped up L31 waiting for a hot 400
Yea those are the less prone to crack ones... so afr it is then?

Well thats good to hear I might use them in the future on a 350 or somthing. And yes I believe Im buying afr 210s or 220s!
 
Joined
Jul 26, 2014
Posts
41
Reaction score
1
Location
La
First Name
Steve
Truck Year
1978
Truck Model
c20 scotsdale
Engine Size
hopped up L31 waiting for a hot 400
I droped off my 400 at l&r and am going to have to go with a .40 over piston. I am getting some machine work done and then will have them help me out with my rotating assembley
 

Forum statistics

Threads
42,158
Posts
910,307
Members
33,655
Latest member
djisurfli
Top