first one is out of a $300 1975 monte i bought in 1987 with the original 454, th400 loaded. numbers are head and block are the same i believe #346236 this is the motor i bored and added trw ls6 pistons that hit the head, they are open chamber so why did they hit? hmm are these heads that good?

next

crew cab with a 70,000 mile 454 i bought the truck for $400 bad tranny, body shot.
head #336781 block #361959 good heads from what i have read. motor looked like new after pulling pan off. i was thinking of giving this some higher compression pistons like the above motor to liven it up. thing is will i have the same piston hitting head problem?

next

this is a motor i traded a 4 bolt 350 short block for. short block has fresh overhaul std. bore. block #3999289 heads were the 772 casting.

also have another block and heads that came with the 68 that is all apart but has a set of 781 heads with it.

still have another that i dropped in my 81 3/4 ton 4x4 i will find out those numbers next. and yes another $400 big block with all acc. with about 77,000 miles. lucky me

thanx for reading and any input appreciated


------------------
fast as fast can be!!!
1966 chevelle malibu454 4 speed

1968 chevelle malibu 454 th400

1981 firebird formula

[This message has been edited by bradford (edited 10-26-2002).]

Hope this helps

Block: 346236.....454.......75-76...2-bolt
Heads: 346236.....75-87...oval...OPEN...454
120cc chamber, 225/116cc ports
Block: 361959.....454....73-90...2 or 4 bolt
Heads: 336781.....73-85...oval...OPEN...454
118cc chamber, 256/114cc ports
Block: 3999289....454....72-79...2 or 4 bolt
some "CE" replacement blocks
had four bolt main caps
Heads: 343772.68-86.oval.OPEN.366T, 427T, 454
Heads: 336781.....73-85...oval...OPEN...454
118cc chamber, 256/114cc ports

Got all the info from Mortec.com

------------------

72 Chevelle SS

sorry should of said i went to mortec before posting this. did some further reading and are the 236 casting numbers really peanut prot heads? god i hope not cause i put some money into them about 10 yaers ago fixing some cracks and new seats.

------------------
fast as fast can be!!!
1966 chevelle malibu454 4 speed

1968 chevelle malibu 454 th400

1981 firebird formula

Sorry, the 236 are the standard BBC truck "peanut" port heads. Still OK for street crusiing below 5000 rpm I think.

if they are truck heads do you know why they came stock on my 1975 monte carlo? thanx

------------------
fast as fast can be!!!
1966 chevelle malibu454 4 speed

1968 chevelle malibu 454 th400

1981 firebird formula

Sure, that was about the time the engines were really poor power producers due to drop in CR. and unleaded gasoline, so they probably just stuck the suckers on a stock, weak at the time engine, and sold the sucker as is!! Just my 2 cents worth... pdq67

thanx pdq67 i should be able to get more performance out of my 66 with the right heads. guess i'll be putting some 781 heads on it.

------------------
fast as fast can be!!!
1966 chevelle malibu454 4 speed

1968 chevelle malibu 454 th400

1981 firebird formula