My engine. Which runs to well to tear it down at this time, is supposed to have an after market rotating assembly in it. The block was sent to a speed shop in the Seattle area and was checked out and had a balanced 427 rotating assembly installed. What I would like to know is if the 427 crank differs from the 390 in just more than stroke. In as much as is the mains larger and needing to line bore the block? Or not. And what is cross section or cross bolt on the rear main. This FE flat gets it on like no 427 I have ever seen. And has few external mods.

 

I am not 100% positive, but from reading up on FE engines, every source I have consulted says that the 390 and 427 (not 428) crank are the same. Identical stroke (3.78"), journals, and even in some cases casting numbers (usually the High nodular iron 390Hi Po cranks)

in fact, the 427 is just a 390, punched out beyond belief (.180" over-bore)

 

The 427 has the same stroke as the 390. The 428 has the 3.98" stroke. The 390 has a 4.05" bore and the 427 has a 4.23" bore. Very few 390 blocks can be bored to the 427 spec.

 

Bear, i don't think any 390 block will go 4.230 and last. Taking .090 off each wall or side may leave as little as .060 wall thickness.

 

I was told my the guy that built it that it had billet main caps and 4 bolt on the rear. He said that the main caps are made from hardened steel and ground to fit. A bullet proof bottom end he called it. I can tell ya this engine really has some hi rev's and they come on instantly. No tach so can't say for sure but it will turn up under a load that sounds higher than any average modified one I have been around. The mud bogs here are running modified small block and big block chevys. I want to use this engine there, but the 66 dually it's in is to heavy I think. But would like to find a short box to put it in as I don't want to cut up the 66.

 

well as mentioned the 390 and 427 cranks share the same stroke. Billet main caps sound excessive for an unmodifed FE, i like to believe theres some goodies in there.

 

We have over 3500 miles on it and had no problems. I was at the shop up here after the engine was bored and magnafluxed or x rayed or what ever ya call it when the machine shop called and said that it took the bore well and had plenty of meat left. And not to expect any hot spots. Said it would go more if they wanted. So I take that as a good block. Right? It has sat way more than it has been driven. I need to overhaul the Holly and tune it up as I haven't fired in in 8 months. But as soon as I can get through the snow to get to it. She will get everything she needs to run as It was built to.

 

im not saying your block is junk or anything like that but if its not a true 427 block i don't it has the 427's 4.230 bore, thats it.

 

Where do I fined the casting numbers to tell if it is a 390 block or someting else. I can get the hood open with a little shoveling but crawling under it is out of the equation. Untill I get it moved. And that will be under her own power.

 

some blocks have casting numbers and others dont. Some of the older block have 352 cast on the front but that is meaningless, the later blocks are mirror 105 blocks. Some of the 427 blocks have identification in the bellhousing area. The mirror 105 blocks have identification in the lifter valley. Odds are you will dirty and need a six pack before you find anything worthwhile in your situation.

 

Have you checked to see if the block has crossbolted mains? Easy to see....look for 3 screws on each side of the block above the oilpan. I can't see someone installing billet caps and not crossbolting it. That said there are those 2 bolt main 427 irrigation/industrail blocks. Someone might have got ahold of something like that. Never know. When you have the time also see what crank and rods it has. It could have a 427 steel crank, LeMans rods etc... Those have been found beleive it or not in irrigation engines before. Rare yes but found there none the less. There are also tons of 428 industrial engines that were made. You could have a 428 with a 427 rotating assy making a 406. Anything is possible......
Matt is right on the casting numbers, most are generic and useless. There are some tho that only jive with a certain block so it can't hurt to see what it is. Also the head and intake numbers would help.

G.

 

I've seen 2 that would. Both were the early 60's high preformance 390s. If memory serves, and it doesn't sometimes, both were 3X2 motors. But hey, that was backin the late 60's and you know about children of the 60's. We were so and used too much weed.

 

This engine came from a mid 60.s Two ton truck. When it was tore down before going to speed shop it was a 390 according to the bore and stroke. I know this as I am the one that cleaned it up before shipping to Seattle. All we sent was the bare block. The speed shop called and said it had lots of meat on the walls and would take it to 427. He called back and said it took it fine. Put in aftermarket rotating assembly and sent it back with a set of modified heads. It was assembled here. I will see if it has the cross bolt mains as soon as I can. And get some numbers off the heads and block. Understand that this was done about 10 years ago and has mostly sat. It has very few miles on it. As it is to low geared to be a daily driver. All it has been used for is a few freight runs and fire wood. It has gasket ported stock intake and headers. The guy paying the bill ran out of money at this point. It broke two high lift cams. each within the first 50 miles of the shop. We didn't know at the time to remove one valve spring during brake in. After the second cam failed the local shop said he was done with it as he would not buy another cam. The owner at that time (my wife's cousin) asked me to get it to run anyway I could. I installed an RV type cam and has been running every since. I got it about fore years ago and use it about once a year to make a freight run. Or get a load of fire wood. One trip just after i got it I hauled a load of plywood and lumber on her 8X12 foot bed stacked two feet over the cab guard as this is where we put the 20 foot 2X6's. And had a 24 foot Fiber form boat in tow. It loaded with the building supplies we couldn't get on the 66. Cases of nails, roofing paper. tar etc. It hauled it well and only on a couple of steep rough spots did I have to drop to 3rd gear. It is possible that it is the factory block and the story of coming from a 2 ton may be bull. Where is the Vin?

 

Arctic..there are several ford blocks that were cast for the 390-427 with thicker walls..and casting where the cross bolts went..in the 390 they just used the 390 bore and did not cross drill the block..the same block can be punched out and cross drilled to make a strong 427..look through casting books and you will find castings for 390-427..put a thunderbolt type cam in that motor and drop in a lite f100 and you will have a giant killer...bill

 

i just recently bought a fe ford engine from a friend who was hard up for money suppose to be a 390 hipo i havent pulled the heads off yet to measure the bore the head casting is C3AE-6090G in my book that shows to be a 427 lowriser head the casting number off the crank is C4AE-B the numbers off the rods are C3AE-C the block is C4AE-A it has a place for the crossbolts but they arnt there.i contacted james lyle he assembled engines for bill elliott for a while and worked for fords race division in the 60s and still does some winston cup cars now he said they were a few 427 ford motors that wasnt crossbolted some of the first ones wasnt according to him.all these pieces in the 2 books that i have say 427 i might have to pull a head and mic the bore and see.has any one ran up on this before this engine appears not to have been disturbed