Hello all,
This fall I'm looking to rebuild the 400 in my 1979 Ford F-250 4x4. It has the NP435 4spd and NP205 T-case. The engine has about 108k miles on it and it's in desperate need of a rebuild. Compression test shows I have a few cylinders that are almost totally dead. I haven't been able to determine whether it was the rings or valves leaking, but I figured a whole rebuild was needed anyway, so I didn't dig into it. The engine is getting pulled, disassembled, and I plan on machining the whole block and heads. It will also get a 4bbl carb, aluminum intake, a mild RV cam (comp cams part#: K32-207-3), and eventually headers (funding permits). I was originally going to use a Sealed Power rebuild kit, but it looks like it was discontinued. I see that Northern Auto Parts offers a rebuild kit. I've heard pretty good things about them. Also EngineTech offers a kit, but I've never heard anything on them. I want a good rebuild kit that wont give me any problems and will last for years to come. I don't want to buy parts twice, so a kit that has everything I need and nothing I don't is ideal for me. I also prefer for things to be U.S. made. If anyone has any experience with the previous kits mentioned, or knows of any other good rebuild kits I would really appreciate the insight. Thank you!

 

Need to get tore down first and check cylinder bore and what the block will clean up at on rebore, .030 or .040 on pistons. Next is get the crank checked and see what spec the crank is at. Might need to turn crank and need .010 under bearings?? Several questions need to be answered. Also if possible have your machine shop use a torque plate when doing final hone on block. these cylinders move around a little. torque plate simulates a head being torqued to top of block. helps ring control. 351 cleveland torque plate will work if your shop has one! talk later.

 

Agree with Wyoming4x4...

Tear it down yourself to see what you're getting into. Heads and Block tanked & cleaned. Valve jobs in order? Bore dimensions will dictate your pistons...what CR do you want? What do the crank and rod berrins look like as well as the crank itself? Cam berrins will need replacing which the machinist should do.

Before you go jumping into a "kit", talk with a machinist/builder you can trust with the lower end. Then you can do some more homework on the DCR/SCR, cam, lifters, springs, rockers, intake, etc.

 

What they said, plus, any "kit" is going to be the stock low compression spec pistons. No need to suffer with the low 8s, 9.3 is easy to find. Also, the stock cam is dog %^&* so figure on a cam set up, including springs, so your valves will actually move off the seats.

TMeyer, Inc. Precision Automotive Machining

You don't have to build a race motor. A decent cam and 9.3 compression will be a major improvment even if you stay with a stock 2bbl and stock exhaust manifolds.

 

Agree!!!!

I am not a "fan" of kits.....for many reasons but mostly 1) they are not comprised of the "best" parts you can get for the $

 

Thank you everyone for the input. I wasn't going to buy anything until the block was tore down and I know the specs of what I need. I want it bored out as little as possible. The main reason I wanted to go with a kit was for monetary reasons. I don't want to drop $5k into this engine. I want a good engine that has improvements over stock that wont break the bank. I was hoping to keep the total rebuild cost under $2,500. Intake and carb will take away over $500 alone. Is under $2,500 an unrealistic goal? I plan on doing the rebuild myself with my uncle. He has rebuilt countless engines, so he can make sure I don't screw anything up.

 

thinking little more towards $3000.00. Most important is get compression up and better camshaft. Talk with tim meyer and saves you a lot of headaches on compression and cam. You can work the exhaust/intake ports and smoothe out and help the flow with simple deburing. Also just port matching with a grinder easy touch ups. Free just your time! Buy a quality timing chain and NOT a 39.95 special chains start to stretch around 20,000 miles and just get worse. giving up horsepower!

 

IMHO...check out the crate engines....you will get a warranty & they typically cost less than if you were rebuilding yourself...especially when you are looking for minor/moderate HP/TQ gains. May I suaggets gofastparts.com...they are located in Redlands calif....their website is not the best but they carry just about every crate engine known & their prices are typically less than the dealers....

 

I also agree with finding a local machinist who is both knowledgeable and trustworthy, not somebody who only knows how to drill holes in iron....

 

X2 on the Tmeyer stuff-good upgrade to the cam bearings also.
also X2 on the strip down first. Really needs to be pulled down and then assess what parts you need.
Get the heads checked also, Standard springs ok up to about 0.5" lift, but need better valve spring retainers (collets) over standard.
Actual heads and valves will also have a say in what cam you run.

 

I'm a big fan of Tim Meyer's stuff. He's just kinda expensive, although I know you are paying for quality. I don't want to do a crate engine because I'm trying to keep the truck as original as possible. If I ever decide to replace the engine I would do a 460 conversion. I'll probably call/e-mail Tim and see what he can do for me. I would like to bump up compression since these 400s have such low compression from the factory. Like I said. I'm looking to do a very mild build. Looking for some better HP and TQ without breaking the bank. I really can't justify spending more than about $2,500. So I would like to make the best overall engine for under that. I guess my first step is to try and get the engine tore down and find a good shop to do the bottom end for me. Then I'll move onto the rest of the build.

 

400's are definitely more expensive to do up than a 351C, but considering you can actually get higher comp pistons over standard, dont think he's that bad is he? definitely not $400 though.
Just feel lucky. I live in Australia and it was still cheaper to import his rebuild kit (with harmonic balancer) than it was to buy it here with standard pistons from the machine shop doing the work.
I havent looked for ages, but from what I remember, he wasn't that far out from anyone else, and if you wanted a fully balanced stroker kit (434) than he's your man. Only approx $2400

 

If you look at it by cubic inch per dollar it evens out pretty good. Actually going in the 400 direction is cheaper. so if you spend $3000 on either engine and divide by cubic inch the 400 wins. this is one way to look at! so depending on application like high horsepwr/rpms would look more towards 351c unless you go 434" 400. but for basic overhaul and upgrade pistons and cam its actually going in the 400 favor! Just thinking about stuff.

 

I spoke with Scott at MPG Heads - at Wyoming's suggestion. (Wyoming - LOL! You recommended MPG to me and TMI to Mike?) Anyway, they have a kit for $400 of Speed Pro pistons that'll give 9:1 CR with the stock heads; rings; gaskets; bearings; cam; lifters; and oil pump. Scott said it is all the "good stuff", like a Melling pump, etc. Sure seems like a good deal to me if you want to stay with the stock heads.

 

. PISTONS PISTONS PISTONS are the main concern with 351M and 400... Use TMI pistons if going off the shelf pistons! ALL general 'rebuilder' pistons work poorly. Ok to get a rebuild kit without pistons for everything else... doing it yourself, should be able to do a great rebuild for improved power, torque, MPG for under $1500...