GoldOlds

Since I still haven't ruled out replacing my Cutlass's 350 with a BBO, I'm wondering how good each of the big block heads are. NOT considering scarcity or price, how would you guys rank them, from best to worst? I realize "J" heads will be at the bottom of the list and "C" heads somewhere near the top, but I'm not familiar with the performance attributes of any of the others. I saw a 1970 Olds 455 in a local ad recently, which I THINK means it will have "E" heads; are those any good? If I get stuck with "J" heads ('73 to '76?), are they workable or would I be better off buying a set of alumn. Edelbrock heads? I'd be looking for about 400 hp on pump gas - nothing TOO wild. My ('69) Cutlass has 3.73 gears, TH350 and 2.25" exhaust. On another note, will the TH350 hold up to a 400 hp 455?.
Thanks!

- GoldOlds

2blu442

I wouldn't hesitate getting a set of C, E, G, or Ga heads. I believe they could all be cut out for the 2.07 valves if you don't get a set with the big valves already. What I understand, and other guys can chime in is that the heads listed will all function about the same in stock form. The C head casting is said to be able to take more flow work and do a little better than the rest for serious performance. I had a set of E's cut out for 2.07 intakes and I think 1.71 exhaust, then he did some flow work for me too. For street performance I wouldn't spend the money the Edlebrock heads cost. Also you mentioned you were thinking of 400 hp, the 1970 455 4bbl engine in stock form was rated at 365 hp with a smooth idle. I would think a better cam and intake then an exhaust system that breaths well could get you to that 400 hp mark without spending a lot of money. My 2 cents worth, but whatever you decide have fun with it! John

dar83501

Firstly, don't buy Edelbrock heads. Although I haven't used them myself, I haven't heard anything to lead me to believe that spending the extra cash on those heads warrants any performance improvements they may have. Also, the horsepower of your engine doesn't matter so much when it comes to what transmission to use, it's the torque. Any 455 is a torque MONSTER, and it will turn a t-350 into little pieces of shrapnel in no time. You absolutely have to find a turbo 400 if you plan on using a 455.

Also...go to a local boneyard and buy some big gnarly engine mounts. You'll need them if the engine doesn't come with any

Olds64

I agree with John. The C, E, G, and Ga heads are all good castings. I believe the J heads are also fine for a street motor. I have heard that they drop off at about 3500 rpm. A BBO won't be revving that high very often anyways.

You can also purchase big valves and have the heads machined to fit the valves. I put a set of aftermarket valves in C heads for Oldsguy when I was in college. I believe they were 2.10 intake and 1.71 exhaust. I am sure Oldsguy would remember for sure. He is still using the heads in the 46 he is putting together.

CHRISH8846

Built correctly a th350 will be fine behind a mild 455 build.It will even take some mild abuse, I have a th350 behind my 461 an it just has a few mods that did not even require the trans to be removed and has worked fine for 3 plus years. As far as mounts go you can buy a set for the 455 that has a anti-seperation plate and for more security if you want it you can run a cable or chain from the frame to someplace on the eng to keep it from rolling over too much.
Lots of guys on Realoldspower.com run E-brocks, some like them some don't ,some run Rocket Racing heads, do some reaserch and make up your own mind.

64Rocket

Any of the castings (A, B, C, E, G, Ga,) are all good choices. The A, & B may need push rod hole work, but all are great.
Now, if you have none consider this,
$100/200 for a good cores
$100/160 for guides
$160 for seats
$250 valve job
$200 install bigger valves
$180 for valves
$150 for good springs

$1300 so far

plus anywhere from $500 to $1000 for real port work. If you can find some one to port steel heads.
Now you can do port work yourself, but are you really doing it right.
Also you may use the stock valves and whatever size they are. But you may need guides anyway. Consider 30/35 year old valves and heads.

Now E-brock heads are brand new and come with big valves and new springs. Plus they flow better than any of the steel castings. You will have to get a rocker arms. I have used the roller tip rockers from Comp-cams. Get the rocker studs exchanged to 7/16 bottom and 3/8 top and away you go.

To me in the long run the E-brock is the way to go.

71 delta88guy

Exactly. Head work is BIG money and you're at the mercy of the guy doing it.Machine shops LOVE old heads. Money pits.With the e brocks you have new ,excelent flowing,aluminum so you can run higher compression ratio's without detonation, save lots of weight,and the list goes on. OR you can do what I did on my first 455 build. I got lucky and got a SET of E's from autozone for 300 bucks.I immediately changes the springs-they were crap- and had a good time with them for 5 years. As you can tell I'm not a big machine shop fan. Good luck.