This year I will be building a 393 and would like some opinions on what parts to use.
Car is a '78 Mercury Zephyr Z7 and will see about 50-50 street/strip usage. (I love to see the look on a person's face when they get beat by a "grandma" car)
So far, this is what I have:
For starters, I already have a 351 roller block and also have a forged stroker crank that I picked up a few years ago from the Motorsport catalog. Heads will be AFRs. Exhaust headers will be handled by Hooker. The engine will see some serious RPMs.
Give me some opinions on the pistons, rods, camshaft and intake manifold. 93 octane is readily available. FWIW, I am an experienced mechanic and will be doing the buildup myself. TIA.

 

I am a fan of Isky cams & vavetrain (I think they are the only ones that check every spring before it leaves the shop). While I'm also not a big Edelbrock fan, I can say that i am very impressed with the air gap series manifolds!

 

The Thumpr cams from Comp are the dog's nuts for a street machine. Well, only if you're looking for a thumping, choppy idle and 20 more hp than their XE grinds.

I've got JE forged pistons in my 331 and no worries so far. I hear Scat makes some good stuff too.

 

you can use 302 pistons with stock 351w rod length of 5.956. Forged pistons are very durable but the most expensive. Hyper are an alloy that can runner tighter piston to bore clearences but are not as durable. Cast pistons are not a good idea.

I would run a solid flat tappet cam because, they are cheaper than rollers, lifters are lighter, needs less spring pressure. Solid lifters are not rpm limited like hydraulics. Your horsepower drops off with hydraulics lifters at higher rpm's vs a solid.

A stock flat tappet hydro lifters fade power at about 5000-5200 rpm, anti pumps are rated to 6500 and solid are as good as the springs will let you.

 

I built a EFI Summit 393 for my 1990 extended cab.It was running 13.6 last summer w/stock non posi 3:55s.There was an issue w/ the bearings touching the fillets on the crank so we went w/ narrower race bearings.I put a Probe main stud girdle and rocker arm stud girdles on the ported Trick Flows over the Crane gold 1.6s.I called Comp for a custom roller,they advised a XFI w/.589 lift.It had enough power to snap the input shaft @ 60 MPH rolling burn-outs.The compression is 9.36:1.I pulled it out a couple of months ago to put in some H-beams in,more compression and change the springs for 1.7 Comp. gold rockers and a little more porting on the heads and intake.The headers need to be at least 1.75"s not the 1.5s that I`m using.Also check for rod bolt to cam clearance.

 

DAMN!! Now that's a motor. I'm guessing that was an AOD in there?

 

It will be a helluva motor... AFRs are great heads and work very well..... Its my opinion that flat tappet cams solid or hydraulic are junk, and if wouldnt run anything that wasnt a roller in 2010... either a solid or hydraulic roller..... the reason I say this is that cam failure with flat tappet cams is a very real problem.... you will have to run additives in the oil or they will fail and worse, if you run a higher lift flat tappet cam, the heavy duty springs required to make the valvetrain operate properly will only act to increase the likelihood the cam will fail...... plus to properly break in a solid flat tappet you should use softer springs on fire up.... so the fuss and muss portion of the build is really there.... I would only run a flat tappets in rig up engines thats just my opinion....

Be honest about where you will actually run the engine... the rpm band is important for the cam you chose.... if you are really building a street machine, which will be primarily be used for cruising go hydraulic roller...... if you are primarily building an engine for competition, where the necessity to spend time running over 5500 rpms is required for a significant amount of time... go solid roller..... since you have an adjustable valve train.... and probably will be running full roller rockers.. valve train adjustability will be easy, because you can do it with the engine running and valve cover off and oil will not be everywhere..... and if you go solid roller and expect a lot of rpms.... get the 7/16 studs, rockers, and stud girdles.... you will thank yourself later.... as well as the thicker pushrods.....

I would advise keeping the rpms down though with a stroker.... engines with shorter strokers live happier lives at higher rpms..... the classic example of this is the FE427 and FE428.... the 428 is a 390 bore with a stroker crank.... the 427 was a 390 crank in a special block with larger than normal bores... the 427 was used in Le Mans adn NASCAR where you were running at WOT for hours.... the 428 was used in drag racing where you were running at WOT for seconds.....

I am telling you this because the larger the stoke you have the more likely you will have a bearing failure or snapped rod at high rpms..... so this is where you want to buy the Fluidampr or Rattler balancer and get the assembly balanced.....

It is also a very real difference of opinion of pistons and rods when it comes to strokers as well.... I like to keep the pistons as light as possible, because the heavier the piston... the more the rod is fighting is as is move it up and down the bore... this is why I usually try to stay away from forged if I can and go hypuretectic if possible..... and if you have to have/use forged.... you want the superlight (very expensive) pistons .... I would also recommend H-beam rods not matter what you choose for pistons.....

Also I think that motor will run well with like a .550 lift cam... I am really not going to say use brand x over brand y because I have used them all and never had a bad experience with any of them...... I look for who has what I need..... hope this helps.... and a 393 will be a monster and you will be happy with it.... just dont get too carried away on the carb.... because its natural to go too big......

 

Yes Conanski,I`ve replaced the broken AOD w/a TCI Super Streetfighter AOD w/hardened input shaft and non-lockup torque converter.It seems to be holding up so far.Still need to convert to posi 4:11s.And a one piece aluminum driveshaft.Still need to dial in that EFI though.