Hey All

I have a 74 Convertible with the base motor and 3 speed auto. I have developed a little leak from the head gasket with the car is cold. Luckily it is not going into the chamber, but rather runs down the back of the block and stops when the car reaches around 200 degrees.

There has been engine work done to the car, I just dont know what was done inside. I have a Edelbrock Performer Intake and Carb. Some say that it sounds like it has a slight cam to it... But I think it just idles rough.

So my long term goal is to buy a create motor in a year or two. Something with 350'ish horse. But for now I want to fix and maybe upgrade the stock motor.

I need new head gaskets, and figured while it was apart, I would slap on a set of new heads. I just dont know which kind. Any suggestions? My friend is pushing me towards the Vortec heads, but I dont see anything listed about my year block.

What do you all suggest as for new heads with improved performance? Am I going to notice enough of a difference to make it work my time? What do I look for when picking the new heads out? Will it say for 350 or are there specific 350 blocks?

Thanks

 

What's your budget? Virtually any GEN I SBC head will "fit". Headers? Rear-end gears?

Vortec heads are about the best entry-level heads out there at an incredible price. The only downside is that they will require a new intake manifold as well. Since you already have an aftermarket intake and carb, you've already sorted out the carb linkages and fuel line...so it's just a matter of getting the Vortec version of the Performer.

Many other options; the most likely choices are the Dart Iron Eagles and the World Product Torquer II's. Good heads the way they sit, and very upgradeable down the line.

If you've got more budget, then we can discuss more options

 

Budget... I'm trying not to go much above 500 for the work that needs to be done now, since my long term goal is just a new block.. So I'm keeping my eye out for something used.

Right now the car has the factory manifold. But I also want to switch to headers with the create motor.

As for the rear.. I honestly never checked. I am thinking something high as it does not seem to have much launching ability.

 

Did you try re-torquing the head bolts to see if that will cure your leak?

 

I have not. Been meaning to, just trying to use this as a reason to make more power..

 

Xterrable
hope re-torque solves it. Also check rear intake manifold bolts for coolant leak.

seems you have an L48 base motor ... those have low-compression dished pistons ... needs more compression to make more power.

the vortecs & others mentioned are all good heads ... but few are available with chambers smaller than 64cc ... 64cc w/ base OE L48 will scarcely yield 9.3:1 scr ... or less.

Perhaps consider good used gen GM L98 aka ZZ4 aluminum heads. Their 58cc chambers will bump OE L48 to about 9.7 - 10:1 scr (depending on head gasket choice). Your OE exhaust manifolds, OE intake manifold or EB2101 intake should fit ... but your OE valve covers & OE rocker arms will not fit/function. Shop around ... good used prs L98/ZZ4 turn up routinely within your stated budget.

nice crate motor is Year One CT350PC1 ... real dyno sheet, 400hp, 400tq, roller cam ... about $3200 DELIVERED ... likely best value out there.

 

That crate doesnt sound bad at all.

Wont make 500 on that shortblock, nor with the Vortec/factory type heads. Basically start all over from scratch.

 

$500 just won't get you to new heads. You can probably get your existing heads a good 3-angle valve job with a 30 degree back-cut on the valves and maybe a light bowl port for about that amount of money....but it's not a great investment. Used heads are a crapshoot of epic proportions - I mostly see junk and racing heads out there.

If you don't have an aftermarket manifold (confused as your original post noted that you had an Edelbrock Performer intake and carb) then you also need to figure in the cost of aftermarket linkages and potentially a new fuel line or at least some work there. Not expensive, but a bit of light fab work to get everything working right.

Given the budget and your future plans, I would just replace the head gaskets. If you want to get a bit deeper, pull the cam just to see what it is...or at least try to do some half-assed measurements of lift and duration to get an idea of what's in there. Hard to be accurate without pulling it, but it would give you a rough idea.

Follow that with a good tune - 99% of "soft" engines respond incredibly well to the right timing and carb tuning, and ensuring the carb is working correctly.

I'd avoid the ZZ4 "fast burn" type heads. The flow is lousy - less than iron Vortecs. It's also not worth chasing CR - at this power level it's worth maybe a 1% increase for each point. You'd pick up a 1.1 CR bump or so from the 76->64c chambers, and that will go up further when you pick the right, thinner head gasket to correct the quench to around .040. Stock pistons are typically .020 or further down in the hole, and many standard head gaskets are .039...since the engine appears to have been apart once, I'd bet money that's what's in there now.

 

199-201 cfm . Dont know why so many recommend them as a performance head they simply arent. Little better than a small valve camel hump thats it.
Intake port and seats are horrible.

 

Well, looking back they were one of the first factory aluminum heads, so they got a lot of airplay. The chamber was great (forerunner of the Vortec) and the flow was reasonable with some serious porting work and sometimes bigger valves. Pretty good heads at the time - there are just far better available today.

 

if you want only 350-400 budget hp from a dished 350, L98/ZZ4 heads will do just fine.

 

Wow, thats a great price for 400hp... Does anyone on here have any experience with the piece?

I keep going around and around.. Now I am back fixing what I got and just stepping up to a create motor.. There are to many options and I dont have the time (or money) to add something only to find out that I need to add something else.

 

Lunati 102 cam and a valve job, headers and dual exhaust.

The headers and dual exhaust would be something you could use with the new engine. The cam is a decent cam, I really like mine.

I built my own dual exhaust for $100.00, mufflers $80.00
Headers from Summit $109.00
Cam and lifters $180 I think.

This with your stock heads should give you an honest 70 hp.

My 75 started off with 160hp. Now I'm around 335hp.
I also went with the ZZ4 heads.


Ralph

 

Ok ill be nicer....lol

If you only have 500 to work with just fix the head gasket and save for another motor. (as said above)


Dont use flowmasters either your car will explde!











.

 

You could buy a really good set of heads to install now, and then buy a shortblock later to put them on then swap the heads over when/if you get the shortblock. Instead of wasting money on heads you dont really want or won't use on the engine in the future. Throw in a good cam and if all else is good you may not need a new engine or even want one. Would cost more now but less later.

 

SOOOOOO.........back to your original problem. Who told you that new head gaskets were needed? You'd more than likely have more than a coolant leak if it was a head gasket. It sounds like your intake manifold gasket is at fault. At the rear of the gasket where the manifold and the head mate up, I always put a little extra RTV sealer so it doesn't leak. That's where the small block usually lets go when there's a coolant leak that runs down the back of the block. I suggest you check it out before you go to all the trouble of replacing a head gasket that probably isn't bad to start with. Good luck and Happy Thanksgiving everyone!
Duane