428 and 360 Questions

[dustman_stx]

First- for clarification, and to expose my ignorance. I would assume that from discussions of using 428 cranks in 360/390 blocks to make a 410 that the distance from center to center of the piston on any FE would have to be identical. Therefore, the wall thickness between cylinders should never change on any given FE bore, regardless of original format. I would come to the conclusion that an engine that left the factory as a 428, 4.132 bore, would have the same wall thickness of an engine that left the factory as a 360, but was bored .080 over. If the wall thickness would be the same, why the worry of boring .080 over?

Also- I've got a 360 in a 72 that I did a ground-up resto on. Has a Performer RPM intake, Holley 600 4bbl, headers, cam(don't know any specifics-not real aggressive, but not stock), Pertronix II ignition and coil, 3000 stall, B&M shift kit with complete tranny rebuild, Trac-Loc traction control system with 4.00 gears. I am running factory heads that were reworked with new valves and hardened seats, but no real performance upgrades. It runs pretty good, but I want a little more out of it for not much money(Already thought about pulling it and making a 390 out of it, but REALLY don't want to go through the hassle). Therefore, I'm thinking a 100 shot might perk it up more to my liking. I plan to run an MSD Digital 6 ignition that has built in timing retard, and I've changed my plugs to Autolite 124's. They are made slightly different from the stock 45's, but I couldn't find a step colder without going to this plug. I am currently gapped at .050, was running .040 with the 45's, but will go to .030 with the 124's with the NOS. Plan to upgrade the fuel pump to, most likely, a 110 GPH Holley mechanical. Am I on the right track, or would anyone offer any other advice?

Thanks in advance to the gurus!!!

[fordman]

the wall thickness is different on those two engines. the center to center should be the same. it will be piston size that makes up the difference on the bore size. the crank will line up fine. the question is wheather or not the block can be bored that far out to do a 410. sonic checking is the best way to tell becasue of core shift and this and that and everything else you may hear about .

[court1100f]

Actually not true in the case of the 410, the 360/390/and 410 share the same bore hence piston size. so all that'd be needed would be the 428 crank and rods and a good set of pistons in the prefered choice of compression ratio to make a 410 out of a 360/390. now what you said is entirely true if refering to taking a 360 out to a 428 bore

[Alvin in AZ]

If the wall thickness would be the same, why the worry of boring .080 over?

Core shift and thinner jackets on certain castings.
There's a "drill bit test" through a freeze plug hole but that only gets you so far because of "core shift".
The later FE's blocks with the reverse 105 tend to be thicker walled than the 352 blocks.

I personally don't know nuthin about it, that's just what I've read over and over, is all. :)

Alvin in AZ
ps- x2 on what Court said. :)

[mrtleavitt]

Actually if you are going to stroke a 390 motor to a 410, you can not use 390 pistons on a stock 428 crank. You need either 410 pistons or 360 pistons.

[court1100f]

Bottom line a 410 Merc Clone with 10.0:1 Compression Ratio, 850CFM Carburetor,high rise dual plenum intake,Stepped long tube Headers, a Comp Cams XE256H,stock ported and polished heads with 2.19" Intake and 1.73" Exhaust Valves. will produce in the ball park of 434HP@5000RPM and 542Ft Lbs@2500RPM Thats a Beast of a motor right there thes figures aren't 100% because I'm using Comp Cams cam calculater program but it gives you an idea. problem is options aren't diverse enough to zero in on a more realistic FlyWheel power output but still it shows that a 410 based engine would Rock and Roll and thats with it calibrated for maximum torque,fuel economy,driveability Just food for though is all not to be taken as representative of what that configuration would achieve in the real world but something to think about, You could get alot more than that on HP or Torque or Both or considerably less

a 390Cid with same parameters comes up with 435HP@5000RPM and 519Ft Lbs@3000RPM

some of the variables it doesn't allow for selecting are the Addition of an X or H Pipe/entering the primary tube diameter,ignition configuration,dual or single exhaust,Exhaust Diameter to the mufflers etc. etc.

[convincor]

Actually if you are going to stroke a 390 motor to a 410, you can not use 390 pistons on a stock 428 crank. You need either 410 pistons or 360 pistons.

360 and 390 "car" pistons use the same piston pin height of 1.753" were 390 "truck" pistons and 410/428 use a 1.678 pin height. No 360 piston will work with the 3.98" stroke crank.
390/410/428 use the same length connecting rod @6.49". 360 uses a 6.538" rod.

[mrtleavitt]

Well, when building a 410, the pistons needed/ required are different from 390 pistons from almost every machine shop who has dealt a lot with FE engines. just passing along info that I have worked out and told from top notch FE stroker shops.

[64squire]

Well, when building a 410, the pistons needed/ required are different from 390 pistons from almost every machine shop who has dealt a lot with FE engines. just passing along info that I have worked out and told from top notch FE stroker shops.

I was thinking to use Federal Mogul 381P pistons that are listed for both the 390 and 410. I have been told they will work when stroking a 390 with a 428 crankshaft. The compression height of these is 1.66. 390 "car" pistons have a comp. height of 1.76.
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