Thread: attempting to rebuild my 390.

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Hey all,
I've inquired on some other issues before and got the answers I needed from you guys- Thanks Much. With that being said, I'm going to attempt to rebuild my 390. I have a 68 Ford Galaxie 500 XL that I am very fond of. First off-I've been putting band-aids on it for years and now I'm finally tired of "McGivering" her. I want to take the time and get it right. I'd also like to add some horsepower if possible to. C8AE-H is cast into the heads... but I have not been able to find a casting on the block yet. I still have some cleaning to do as well. Are there any specific places I should be looking for the block size info?? Would I be better off to go with some aftermarket Edlebrock heads or some sort of performance package? I've also entertained picking up a crate engine as well. Would it be best to go with another big block? Would a small block mount up to the transmission etc.??? Basically what is a good starting point for rebuilding this Bad boy?

Lots of options.... 390's are a very good engine IMO. Check for a casting number on the block above the starter pad....

We have some very sharp FE guys on CHR, Barry and FFR to name a couple of them. Both are also very good at helping you with the casting numbers and helping select the right parts for a rebuild... Barry also sells parts at Survival Motorsports---good stuff.

My suggestion would be to get the engine out and apart, get all your block and head numbers, and decide how you want to build it... figure out your parts list, or buy a pre built short block and aftermarket heads... Kind of depends on your budget and how much horse pressure you want.

As with most any project on a car or anything else, Plan your Work, Work you Plan!!!

Hey Dave,
Thanks for the quick response. So does a crate "Short" block come without heads? I guess Im not sure of the difference between "big" and "short" block. If so do have any recommendations for a maker? Can you possibly elaborate on how boring the heads or engine works? I think I'd be happy with 400 to 500 horses. I have no plans to go racing though, I'd just be able to smoke the hopped up rice-burners when they issue a challenge.lol.
Thanks so Much
-Sean

A short block comes without heads, a long block with heads. Boring the cylinders makes the bores bigger and requires oversize pistons. A good set of heads would have larger valves, better valve springs, and some porting work. Barry at Survival Motorsports sells engines any way you want them done or custom built... might want to check out his web site for some ideas and pricing information, good place to start planning what you want to build....

Hey Dave,
I'm still on the fence about just buying a crate motor or spending the money to re build what I have. I'm still trying to actually figure out if it's truly a 390. I don not know the history of the car. I know the VIN number says it originally was built with a 390(2V reg. fuel). The heads are C8AE-H. I cannot find a number on the block though. The block has a few marks but I have not been able to find any number sequences yet. I think I'll have to get it completely out maybe. There is an "X" on top in the oil Valley- it's about 2 inches in size, and also a 44 just above it. The front has a 352 with a 54 not far from that. Just below the oil filter there is a -W- with to screws embossed on each side of it. and there is also a V next to that. I also found a DIFF mark as well. Any help would be much appreciated.

Arty is your engine original to the car? Sounds like it might be by the blocks date code. If so it's nice to keep and use the original engine and just keep whatever parts you don't use. It's only original once as they say. It's normal to not see a casting number on the block from 68 up. Not a big deal as they were generic anyway for the most part. What kind of budget have you set for this? There are a few different ways to go.

FFR I appreciate your help! I got the old bugger pulled today. So it's celebration time I lost my virginity.lol. The only problem was when i pulled it I broke a piece on the bell housing, maybe where a stud goes in at? That's what it looks like. Anyways. After I got it out and cleaned up a tad more, I found only 1 more nunmner on the back end driver side. : 8J175838. I've got the Steve Christ book on rebuilding Big Blocks. I read in there, that 428's have dishtop pistons w/ 4 eyebrows. Mine are like that. They look the the picture int the book that says the compression should be 9.5:1. regardless I need to find out what I have before I decide on what to do as far as replace/rebuild etc.. If I have something worthwhile that I can get some performance out of Then I'll get this one all cleaned up and stuff. If it is just a standard model that will cost as much to rebuild as it would to pick up a crate motor with higher performance than I'll go with the crate mortor. I want to get at least 400 HP put of it. I saw that a builder called "Tuffdawgs"
offers that kind of 390 for about $3700. can you tell anything from that number I found? - 8J175838- This was at the rear driver's side of the block.
I don't have any plans for the drag strip but I would like to be able to hold my own when I pull up to a "rice burner". Once again FFR thanks for everything.
-Sean

That's normally the area where the partial VIN stamping is found.

I was able to get a number off the connecting rods- C7AE-B. the pistons are skirted. I have not taken the the crank out yet. but did see 2U on it. Can 428 pistons and rods be used on a 390?

They can in some cases if block thickness allows and it would be a 406 displacement. 4.13 bore x 3.78 stroke. The pistons should have a size on them like STD-.010-.030 etc.... Home Depot sells inexpensvie dial calipers. Maybe pickup or even borrow a set and see exactly what the bore size is.

stock 390's have a bore of4.05 and a stroke of 3.78. the easy way to increase cid is to get some 410 pistons rods and crank and with no machine work you have 20 more cube's.410's were found in mercury's. with the longer stroke gives more low end torque. what year is the 390? i've built up several 428's in the past and they all had 352 cast into the front of the block.


also have the block sonic tested most 390's won't take the overbore to make a 406. a .030 or .060 overbore on the 410 pistns would be ok but i'd go with n.030. 410 is 4.05x3.98. it's basicly a 428 crank in a 390 block with different pistons. and as far a smoking hondas i think your barking up the wrong tree. i've owned several honda h/bs and with a little work can be real killers.also what transmission do you have? c-6,3-speed manual,4-speed manual.if you have the c-6 your going to need a shift kit in it.after a good rebuild.

Great advice. from all you guys. I think I'm leaning more towards a crate motor at this point. Any ideas where I could sell a tired 390... It is original to the car but I just cannot part with my Galaxie.