350 Motor I think

[tanman722001]

Hi guys,I just picked up a motor with roller rocker and alum intake a holley 4bbl.With a engine stand too.I was wondering if anyone could tell me anything with the numbers off the front passenger side.Thet are KO426DRH.And there is another set under them which is 190291499.Thanks Tony

[67c10rustbuket]

DRH on the suffix code = 1979 350cui 170hp 4bbl carb with auto trans, "F" or "B" body car. The casting on the rear just behind the driver cylinder head may tell you more... probably 3970010, take a look.

[tanman722001]

Thanks I will get those number later on.

[tanman722001]

The numbers on the behind the head looks to be 3970010.Does that say anything else about the motor?And how can I tell what heads I have the only number I can find so far is between the rockers and it is 14022601 and that number is on both.Are they a good head or not?Thanks in advance Tony

[GASoline71]

Those are 305 heads... Definately choking the engine. A lot of cats think that putting 305 heads on a 350 makes more power because of the smaller chamber makes for more CR. But they suck when it comes to air flow... so any gain in CR is lost due to crappy flow.

Plus the valves are smaller than a 1.94 SBC head.

The 3970010 is one of th most common casting numbers GM ever made. Just a run of the mill 350. Good engine. Just ditch the heads. MAybe a 305 guy will want 'em.

Gary

[ka_jd7and1]

3970010 was a very common 350 block casting number.

601 heads are 58cc chamber, small valve 305 heads. They will raise compression quite a bit but aren't "performance" heads by any means.

[tanman722001]

So what heads should I look for?

[67c10rustbuket]

Originally Posted by tanman722001

So what heads should I look for?

Depends on what you want to do with it. Stock was probably 333882 heads(1.94/1.50/76cc), thatys my guess anyway. If you want more power I would look for some 96-98 vortec heads but that requires a special intake manifold as well.

[tanman722001]

other then the heads and a special intake do you have to do anything to the heads?Or can it just bolt on and go?

[400smallblock]

you will need center bolt valve covers too with vortec heads. also self aligning rocker arms.the rockers on your current engine are the same ratio but the slot in the head where pushrod comes through keeps the rockers lined up with the valve. on the vortec heads the rocker arm keeps everything lined up. maybe try and find a set with rockers and valve covers as a unit. seperatley it could be costly. if you plan on running a cam with .470 lift or more, the valve guides will need cut down and heavier springs installed. unless your looking for a high performance street engine i would suggest trying to find some #993 heads. ive used them on several mid performance engines. they are a heavy casting used on gm goodwrench replacement engines and on cars and trucks in early 70's. your valve covers and rockers from your 305 heads will fit them.

[tanman722001]

ok,are the 3986339 or 3932441 head any good both are 76cc heads but the 398 have 1.72/1.50 valves and the 393 is 1.94/1.50.I found those two so far.and two different 60cc heads but they are from a 327 motors.both have the 1.72/1.50 valves

[GASoline71]

Unless you're building a rocket motor... Any 1.94 head will be just fine. If you run open chamber heads the CR will be less and easier to burn regular unleaded fuel.

Gary

[bobs86silv]

The 441 heads are going to be early 70's heads. Will be the heavy style, which is less prone to cracking. They have decent intake runners for factory heads. If you have a big pile of heads to choose from, I would look for any that have the bigger valves, (1.94/ 1.5) Then look at the outside edge where it sits on the head. The older heads will be straight across, with maybe a small cut out or two. The lightweight heads, 78ish on, are scalloped between every bolt boss. Depending on how much you want to spend, I would let the condition of the heads effect my decision. Look for valves that are sitting up high in the chamber still. Check rocker studs for gouges and condition of threads throughout. It can get expensive re building a set if they are in iffy shape.

[GASoline71]

Or... you will spend dang near the same amount to have a set of heads reconditioned as you will on a set of new aftermarket Vortec heads.

Gary