Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (
-   Engine (
-   -   sbc heads (

shieldbreaker 08-23-2005 11:21 PM

sbc heads
i have a set of 3998993 heads manufactured i believe in 1992 (J162 is the code on the heads) i have the heads manufactured from 1985 0n , the 1971 - 1984 heads were made for the 305, 350 and 400 sbc , i cannot find any referance for 400 heads after 1985 under this casting # i noticed that the 400 heads in the pre 1985 had the 1.94 int. and 1.60 ex valves where as the heads for the 305 and 350 engines had the 1.94 int. and 1.50 ex valves, are all the 1985 heads the same or are there a different head made for the 400 like there was for the 1971 - 1984 engines ? if so how can i identify them without removing them from the block and what valve sizes are common for these heads? i am just trying to figure out exactly what i have :confused:
i have checked on the mortec site and a couple others that i have and cannot find any reference for any 400 sbc heads with this casting #.
can someone please enlighten me or point me to a site that will help me determine what heads i have ,,,
thank you in advance for any help given :)

DoubleVision 08-24-2005 07:16 AM

The 993 casting went out of production in the 70`s. However, Goodwrench later picked the casting back up on there targetmaster crate engines, you should see "hencho en mexico" on the casting, meaning, made in mexico.
These heads are heavy casted, 76cc chamber, 1.94 intake 1.50 exhaust.
305`s never came with these heads from the factory, 305`s have 1.71 valves and 1.84 inch valves on the intake side, since a larger valve will likely hit the small bore. The 400 small block was made from 1970 to 1980, so what you have is heads off a 350 if your certain they were made after 1985. Look on the block, if you see the same mexico casting, you have a target master block as well.

shieldbreaker 08-24-2005 10:00 AM

sbc heads
i hope this link works , here it shows this head being made after 1985 , or am i missing something :confused: my heads have the 3 accessory holes shown in the lower part of the diagram (1985 on ) which is identical to the heads i have.
i dont have the mexican made stuff there is nothing marked to indicate that being the case .
my block is american made 350 4 bolt main , now a 355.
thank you for your input to my question.


DoubleVision 08-24-2005 02:59 PM

Look again at the pictures, both heads have the accessory holes, Chevy began adding these holes in 1969. Does your heads have the casting mark on the front of the head? if so it`s a early 70`s head, if not it`s a target master head, as it says on the link you gave.

gizmo-1948 08-27-2005 03:48 PM

Well--my references say that you have a set of (J162) October 16th 1972 production 1.72int and 1.5exh valved heads that were used from 68 thru 76 on 307 and 350 engines found in everything pass to truck, and in the 72 200hp Vette. These heads are considered dumpers--small valves/large chambers--maybe you can find someone restoring one of those sluggish Vettes and get rid of them.

shieldbreaker 08-27-2005 08:12 PM

sbc heads
they may well be the 1972 heads ? but they most definatly have the 1.94/ 1.50 valves and they do perform fairly decent for cast iron heads ., they did have some machine work done to them before i got them exactly what was done im not sure , i guess i,ll have to track down the guy that had the work done and see what all he had done .

thanks for your input :thumbup:

All times are GMT -6. The time now is 08:53 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.