The block is in the shop now and the the bores are fine at .040. It had to be line bored though. If I cant get the pistons that I need I might just live with the low compression for now and look for another block to build up. If that is the case what cam should I get?

 

Your cam selection really depends on what you want to do with the truck. You wouldn't want some wild-assed strip grind for trailer towing. Or vice versa. What engine do you want to put it in, the current low compression one or a higher comp moor?

 

Baddad457

I am leaning towards the low compression for a daily driver. It is a 1966 F100 2wheel drive. I only drive to work once and awhile. The rest of the time I take the bus. I really need it for the weekend projects. If I don't get it runnig soon I might be sleeping on the couch.

 

If you're gonna keep the low compression pistons, then you really need to go with a cam that will compliment them, not a long duration/overlap grind made for high compression. Look for something with as much lift with a shorter duration ( like in a 260-270 degrees advertised or 195-210 @ .050) The RV type will most likely fill the bill.

 

This cam is a clevite 77 rv torque cam that is in a kit with new pistons on E-Bay from Maddog Racing.

(484/510 lift, 270/280 adv. dur, 204/214dur. at .050", 112 lobe spread)

Does this look ok?

 

C8's have 71-74cc chambers, D2's have 68-71cc chambers. Probably doesn't make a whole lot of difference, but there IS a small difference. They will flow the same though. Not to mention that the D2's have hardened exhaust seats.

 

Rusty70f100.

I already had the seats put in the C8' and they ran fine until I started loosing water. It turned out the #2 cylinder has been scoured by what looks to be the wrist pin. I haven't taken it appart yet but I can see that much with the head off.

 

I've got both C8's and D2's in my shop and they both have the same chambers. No difference whatsoever. The 71-74 cc FE chambers are shaped differently. As in the older C4AE's and the 428 CJ/LR 427's.

 

That sounds like the same Summit brand cam I ran in a 400M with 8.0 to 1 compression. The lobe specs are the same.That one worked great in the low comp 400M. So I'd venture to say it'll work fine in your 390. It'll idle like a stock cam, but the power over a stocker will be vastly improved. I've seen a lot of aftermarket, "generic brand" cams with that same profile, I'd bet they're all made by the same company, could be Crane, Comp , or another.

 

Sounds right baddad...they both have the same chambers accourding to all the specs i have 68-71cc.

 

I just found a set of Pistons-Silvolite 1130-.040 with rings and pins on e-bay. Will these bump up my compression little?

 

Not sure which heads Silvolite uses to figure the comp ratio, but I came up with a 8.5 to 1 ratio with your heads and those pistons. Swept volume is 813.8 , I used 70 ccs for the head chambers, 9.5 for the gasket, the dish in those pistons with the valve reliefs is around 22 cc's, and add in another 6.5 cc's for the deck clearance ( -.030 ) I'd hold out for a set of the flat tops. Or worse comes to worse, you can mill .030 from the heads and deck to pickup a few points, I'd steer clear of that route though, it'll complicate the intake fitment.

 

I am going to settle for 8.5 then. I want to get back on the road. I will look for another block to build up for serious performanace.

 

I used H304P's in my engine and have abut 9.3:1 with c8's. They are for a 1968-69 galaxie 500 with an Fe in it. They are not forged but are hyperutectic with scuff resistant coating.

 

I found a set of .040 pistons with rings and pins. They are Silvolite 1130+40. They will be here wednesday. The rotating assy will go to the shop for balancing thursday. I have a set of C7AE-B rods that I plan on using if they check out ok. I might debur the block if I get really motivated. Has anyone done this is it worth the time?