Hey guys, its me again, still working on my school project. I want to improve the displacement on my 360 engine. Now I heard somewhere that I could drop in a 428 and use the stock rods and stock (well, speedpro .030 over) pistons to make my motor a 410 mercury. I used to have a parts interchange book, but I dont know where it got to. Will this work, can someone send me the dimensions between the two? thanks guys

 

Use your 428 crank, the stock rods (or use C7AE-B rods, they are 427/428 PI) with ARP bolts. One option for a 390 block pistons is to use the low compression truck pistons ( I used Silvolite cast pistons). I believe theres a simple way to do it for a 360 bore. The crank puts the piston 0.10 inch further up the bore, the truck piston pin is offset 0.10 closer to the piston top, so you end up with about 10:1 compression if I remember correctly. I chucked my pistons in a lathe and cut the piston recess deeper for 17 cc dish,and still had a thicker piston top at center of diameter than Silvolites 8.5:1. My static compression ration is 9.5:1 and dynamic ratio is 8.0:1. I run on regular gas with no detonation ever regardless of load and trany gear used. I decked the block to set the quench clearance between piston top and cylinder head at 0.038 inch with head gasket in place. I used felpro gasket at 0.041 thick, but am told use a steel shim gasket with copper coat sealer which is what I would do next time to reduce cutting the block deck.
Someone else on this forum said they used some other piston that had the correct piston pin height to produce the same result.
My 416 (0.030 overbore) has great torque. I used Comp cam 260H which has good low end torque, but lacks mid range and higher pulling, so I am trying Crane 266H which has a little more lift and more duration too. I work my F250 4x4 so can't have too much cam as it already surges at real low speed crawling up steep hill with heavy load. A rancher friend has 390, and wants my 410 with way more torque everywhere in the rev range. Just my 2c worth, hope it helps.

 

well my motor is a truck motor, and i believe i got the appropriate speedpro truck pistons, not sure what the compression is, now this is a 360 motor, with the 360 pistons. so if i understand u correctly, i can drop in the 428 with low compression truck pistons correct?

 

Yes. I am not home with my books and don't know the stroke for 360. Go to where you bought the pistons and look up the piston pin height for your pistons verses a stock 390. Your truck piston pins should be 0.10 closer to the piston top than the 390, so your piston will sit lower in the cylinder bore by that amount. This will offset the longer stroke of the 428 crank.
I now do what Smokey Yunick suggests. Put the engine together the first time as you check the fit of each and every part. The final time you go together is for real to install in the truck. I put the crank in the block with engine oil on the bearings, then added ONE piston/rod with no rings, used magnetic dial indicator to verify piston at TDC and measured the clearance from piston top to block deck. This will verify all your parts are compatible. I then sent the block to the machine shop, had block decked some, then did the whole deck measure thing again, and sent the block back for final block deck cut so I knew it was on the money.

 

I just went to Google search.
360 Bore x stroke = 4.05 x 3.50 Rod lenght = 6.54 (long rod)
390 = 4.05 x 3.78 Rod length = 6.488 (short rod)
410 = 4.05 x 3.98 Same rod as 390
So you will need to replace crank, rods, and pistons to make a 390 or 410. DSC motorsports has finished sets of 390 rods. If you buy a set with polished beams (lighter weight) and take a little weight off the pistons then have the assembly balanced you can internally balance the 410. As with any change like this it would be advisable to balance the rotating assembly.
One comment is you could make a 390 much cheaper than a 410. My old 390 was real good, but my 410 is better, more torque everywhere in rev range.

 

yeah, thank you very much, i really want to do the 428 in it, but they r a bit pricey and hard to find (i think close to a grand at advance auto parts). so for a back up plan, can i drop in another crank and still keep the same rods and pistons? (ie 390 crank)

 

I just added more info to my last post. You will need different rods too. I have heard opinions that the 428 bored over has such thin water jackets they can overheat or have bore flexing problems. The 360/390/410 overbore leaves you with a stronger cylinder wall. JMO.

 

410=390 low compr truck pistons, 390(428) short rods, 428 crank. Have it internally balanced so you can run any 360/390 flexplate or flywheel.

--Mike