Hi to everyone!

I have just come home with a 56 Ford F100 from California that is in great shape... very little rust. The questions I have are around the Y-block that came with it.

It was in some state of rebuild with no information on what was done (and now way of asking). I've torn it back down to the block and heads and this is what I have found:

Block - ECG
Heads - ECL-A
ECZ 9425-B Manifold
Older Holley 4 Barrel Carb
New water Pump
New Fuel Pump​
The block was cleaned and it appears that new bearings and seals have been installed as well as Pistons and a new Timing Chain and Gears… I can’t tell if the cam is new but I would assume so, but I have no idea on what the specs are or manufacturer. But from what I can see from the bottom side is it appears that the cylinders have been bored and the pistons look new.

The heads I see are low compression with the smaller valves... I have not removed the heads to inspect the bore or any work that might have been done to the heads.

I'm not looking for a Hot Rod here... just a mild performance Y-block... something that performs well and has some get up and go when you put your foot into it. I’m planning on restoring the truck with a few modern upgrades… not a lowered street rod.

My questions are:
1. Should I remove the heads to determine what has been done as far as bore and what pistons have been installed as well as what work has been done to the heads, if any?
2. Is there a way to determine the compression without removing the heads?
3. Are the ECL-A heads even worth keeping? Should I replace them with the larger valve ECZ-G heads?
4. Is there any value to keeping the ECL-A heads? Will they be a large loss of power/performance? Will I even notice??

Thanks,
Kevin

 

Hi Kevin.

I'm new to Y-blocks myself (despite the sobriquet) but I've done quite a bit of research in recent weeks.

There are a few online resources (including here) which cover the various castings and part numbers, and their relative outputs, desirability, etc. I like Tim McMasters' site "Y-Block Guy" personally as it's a very concise source of information. I'm not on commission, so there are other sites if that doesn't suit you. His head chart will tell you what valve sizes, power outputs and so on relate to which part numbers. Also the combustion chamber volumes, so you can get an idea of compression ratios.

My personal opinion on the G heads is that those are the most sought-after and therefore will command higher prices, if there is any availability at all. Note that other castings also utilise the large inlet valves, not just the G.

Even crappy old truck heads (C1TE for example) can be made to work nicely with a little effort. It all depends on how important improvements are to you, and what they are worth to you in cost, time, inconvenience, etc. And you may find that a good set of headers and exhausts improve matters above what just a head swap would do.

If all else fails, have a look at Mummert heads and oher performance goodies - brand new castings with notable performance improvements. So you don't necessarily have to scour the land for the original bits. Again - how deep are your pockets?

Hope this helps in some way.