Fairly fast... not like race car fast but I want it to be able to get me from point A to point B pretty quick

 

You should have the new to you heads cleaned and cheacked for warpage and cracks before bolting them on. so it would be a good time to have them machined since they are checking them over anyway.

 

The factory springs were designed to work with tiny cams for the lowest price. If you are going to put money into an engine make sure you do not skimp on important items. That holds true for machining.

The heads you get from a junkyard are going to need refurbished anyway, so you might as well pony up for decent springs now as well as any required machine work.

 

That's what I was thinking cause I would get a valve job on them and thought they could just do the machining wile they have them

 

Is there a certain type of spring you would recommend? Or just use the ones that comp recomends to use with the cam?

 

In case something bad happens, a wiped cam lobe for example, I would use the springs from Comp to keep the warranty intact.

 

My point was that if you're trying to build a higher horsepower engine you should not be picking which spring to use based on whether or not you need to have some machining done. If you're going to be spending money on a bunch of stuff including a hotter cam, pick the springs that will work best for the cam.

 

Im more of trying to pick wich cam will work best. If say the 262H or 270H would be the absolute best choice I would buy new springs and I would have the machining done. But if I buy the 254H then I don't need any machining and will buy new springs... I'm just making sure that I don't have to spend money where I don't need it cause if I got the 254H and got the heads machined that would be wasting money cause it's not necessary

 

Ok, that makes sense.

 

Bout time I make sense haha

 

Assuming you get GT40s from a late 90's Explorer you still have almost 20 year old springs. Since you have the heads torn down to be refurbished it is a WISE idea to install new spring regardless of which cam you install IMHO. It's only a few dollars more to have the shop do a little machine work to use the heavier spring for the 262 or larger cam.

Penny wise and pound foolish.

 

I like that saying there at the end haha... but that is true and the more I think about the more I realize that I'm better off getting new valve springs.. especially since I want this motor to last for a good long while... do u have any idea how much it would cost to get the heads machined for the 262? I'm leaning towards that one since its not to big and seems to do what Im looking for

 

Local pricing for machine work and parts widely vary. Call a few shops to get a ballpark figure.

The last machine work I had done was 24 years ago. The heads on that 400 were completely rebuilt. I recall it was ~$300-400 worth of work. Then the motor..........Long story short a complete engine and transmission rebuild on my old 1978 F150 Supercab 4x4. 24 years and 3 owners later the truck is still running. Ironic my next door neighbor owns it

 

That's pretty sweet your neighbor still owns the truck... I got a couple names of machine shops I'll call around once I get the gt40 heads... gonna try to make a trip to the u pull it yard this weekend

 

Is there anything I could do to make the stock 351 heads better or are they just plain junk? Just plain junk

Also are 351 cleveland heads better than GT40's on this motor? I would not say better, but I will say they will take a special intake to work on your 351W engine.

Will the intake I already have for the stock heads fit with gt40 heads? Yes, but the stock truck 351W EFI intake is the next bottleneck to overcome.

What about my headers? Your headers will fit a GT40 head, but more than likely not the GT40P because of the weird plug angle.