Anybody build a 427 with a 454 block & 396 crank?

[Ironangel]

Like the title says...I blew up my 69 L34 396...My machinist buddy thinks I ought to swap over the crank, heads, and intake with new forged domes and a solid cam and lifter set up to a 454 block. Thoughts or experiences? The heads are closed chambered 3964290 cast oval ports. I also have access to a set of 781's...Pro's & Con's lets hear em! PS. This is an economy-build or I'd go full roller...Thanks!

[71Dragtruck]

If you have the parts, or have to buy new ones anyway, I'd do the 427 over the 396, the extra cubes will make more power.

[Ironangel]

Thats the plan. I picked up an RV 454 with 42K miles on it for $150 hoping it was a 4-bolt block, it's not. No big deal because an ARP stud kit and balance should keep it alive in the 7K rpm limit. Would like to break into the low 12's with this motor running a solid lifter cam with forged domes. Just got the motor tore down today, inside was clean, all the journals looked good. What I found surprising was the plastic timing gear, normal slack in the single roller chain, but both front oil galley plugs appear to had been drilled with a 3/64" bit? The oil filter housing had an extension on it with two cut off nipples still attached? It appeared to have been remote oil cooler lines? I thought drilling the plugs or just the right galley plug was a builders trick although this motor appeared to be stock? Maybe something only RV motors got? I had an L34 396 out of a 69 SS El Camino, it had 0.060" over 25cc forged domes, (408ci) 101cc closed chamber heads, and a Comp Cam 268H cam with roller rockers. I was turning 14 flat in the 1/4 with a built 350 turbo and a 4:56 12-bolt Posi...Until it threw a rod right out the side of the block @ 6K rpm. I bought that motor already built, hoping to go faster and live longer with this 427...Thoughts?

[68bowtie]

Yes! Sounds awesome. I’d love for you to do it so I can copy you after I throw a rod out of my 396...

[RustyBucket]

Saw this thread & wondered if you'd put this combo together. I've had an assembled 2 bolt +.30 454 block/ 3.76" steel crank short block on an engine stand for many years. I bought it assembled for a project and never completed it. It's fresh, never been fired & has domed forged pistons(don't remember the part#). I have a pr. of 063 closed chamber heads w/2.19/1.88 valves. Tell me you assembled yours & how strong it runs... inspire me

[rat454ci]

I ran a 3.75" steel crank and .125" over bore in a 454 4 bolt block. I still have the crank rods and pistons. The combo made 451ci. aluminum rods and 12.5:1 forged pistons with open chamber heads and a solid roller. It pushed my 69 Chevelle in the low 10s. The thing would turn 8500 RPMs. I sold the car and kept the engine. I took the rotating assembly out and went with a 4.25 stroke crank. I don't think I will ever do anything with the 451 parts if interested.

[Ironangel]

Originally Posted by rat454ci

I ran a 3.75" steel crank and .125" over bore in a 454 4 bolt block. I still have the crank rods and pistons. The combo made 451ci. aluminum rods and 12.5:1 forged pistons with open chamber heads and a solid roller. It pushed my 69 Chevelle in the low 10s. The thing would turn 8500 RPMs. I sold the car and kept the engine. I took the rotating assembly out and went with a 4.25 stroke crank. I don't think I will ever do anything with the 451 parts if interested.

Wish I would have seen this a week ago...Although the .125" over is .065" over my current set up...I went with a .060" over 454 block pushing the 427 out to 439 cubes. JE forged closed chambered domes, 12.5:1 CR with a Clay Smith solid lifter cam, https://www.claysmithcams.com/c-304-...d-flat-tappet/ ...I'm using Howards .020" EDM lifters to help keep everything oiled while that thing spins up 7000+ rpm...I'm hoping to turn low 12's maybe high 11's with a 4:56 posi and 4000 pounds of 72 LWB Chevy truck...

[kwmech]

That's what GM did back in 1966

[Ironangel]

Originally Posted by kwmech

That's what GM did back in 1966

That's what Mike's doing in 2019...Going with JE closed chamber forged domes. The CR will be 13:1 which will require 110 octane. Clay White solid lifter cam C-304-8-B with a 258 duration and 108 LSA with a .615 lift. We balanced the rotating assembly to within 1.8 grams. I bought a lifter bore grooving tool to aid in keeping the cam lobes oiled. The 454 block was bored .060" over bringing the cubes up to 439 cubic inches. Should be a monster of a little big block...

[Keith Seymore]

Originally Posted by kwmech

That's what GM did back in 1966

Came here to say this...

K

[85_prairieboy]

Your engine is nearly identical to mine. I ended up with 11:1 compression. Same displacement and heads but different pistons. We put bigger valves in and some port work. My car is 3200 lbs with a 4800 stall. So far best time of 10.60

[darkhorse970]

I built one with 454 block 30 over, closed chamber heads, 10:1 compression, and mild 268 XE Comp Cam. It made 491 Hp and 546 ft/lbs at the crank. It’s going on my ‘67 GMC project. Should be fun on the street!

[Ziegelsteinfaust]

I would go full roller. Simply for the fact that today's common part house available oils do not support flat tappet cams.

This way you can run cheaper oil with high reliability, and after a few years the savings would be eaten up by higher cost oils to make a high performance or higher tappet pressure on the cam lobes last with the needed zinc.

I dont know if this is true but supposedly VR1 racing has less zinc now, and diesel oil is almost down to modern oil standards. Which won't support a flat tappet can at the spring pressures nessacary to turn a BBC to 7000rpm.

[Ironangel]

Originally Posted by Ziegelsteinfaust

I would go full roller. Simply for the fact that today's common part house available oils do not support flat tappet cams.

This way you can run cheaper oil with high reliability, and after a few years the savings would be eaten up by higher cost oils to make a high performance or higher tappet pressure on the cam lobes last with the needed zinc.

I dont know if this is true but supposedly VR1 racing has less zinc now, and diesel oil is almost down to modern oil standards. Which won't support a flat tappet can at the spring pressures nessacary to turn a BBC to 7000rpm.

Wanted to go full roller but my pension would only cover an old school bullet proof budget build. JE custom forged closed chamber pistons with 39cc domes pushed the CR into the 13's...Cost of oil is nil compared to 110 octane rocket fuel! I took the 454 truck rods and reworked them to be floaters and balanced them with the pistons to weigh 1251 grams each, dead nuts. Then I balanced that 396 crank to within .08 grams to insure minimal work for the Scat internal balanced 8" damper...I get the Weiand 7620 oval port intake next week to complete the build. I'm hoping to break into the low 12's maybe high 11's with a 4:56 12-bolt Posi and built 350 "Super Turbo"...Thanks for commenting, here's some eye candy!

[Ironangel]

Installing the cam...

[Ironangel]

I dropped the 427 in yesterday only to find out those Moog 81114 springs are worthless. Truck bottomed out to the stops! Going back to factory BB coils with a half coil cut off. Any recommendations? I installed a new pair of HD single action gas charged Monroe shocks with the hopes that those springs would unload and stay up with the help from the shocks...Bummer, I don't know how anybody could run that spring full length and not coil bind it let alone getting it in! Sucks!

[71Dragtruck]

I tried same thing once with Moroso springs, was all good and then next morning was sitting on the bump stops.

I ended up running a new set of stock small block springs and drop spindle with my big block and a set of QA1 adjustable front shocks.

Now I have IFS with coil overs and a manual rack.

[regan wilson]

I used the 6 cylinder springs for years I had probably 3 sets of them. They were a Moog part number. Can't remember which one.

[Ironangel]

Right on guys, thanks for the ideas...I had a set of factory 1/2 ton coils with half of a coil cut off to raise it up to clear 275/R60 BFG's. It has the 2-1/2" drop spindles as well. I think a fresh set of 1/2 ton coils with adjustable shocks will get me close enough for a start. I had two of those aluminum twist in coil stiffeners screwed in on each side to stiffen the ride when I dropped the big block in it 3 years ago. Oddly enough they worked. I was thinking a taller slightly weaker spring would unload and stay up as long as the pedal was down and pulling...I'm tempted to try the 1/2 coil cut off on a set of 3/4 ton coils to support the weight of the big block...Waiting for my pension check...Thanks again!

[Average Joe]

Any updates on this? I Just read through this thread and was wondering if you got to make any passes with the new combo?

[Ironangel]

Originally Posted by Average Joe

Any updates on this? I Just read through this thread and was wondering if you got to make any passes with the new combo?

I got her broke in and running like a top, then I found fleck in the oil! :O It was shiny fleck like hard facing off the bottom of a lifter, almost like ground up chrome plating. So I pulled the motor and put her back on the stand and began the tear down. Lifters and cam were fine, all the mains and rod journals looked excellent, then I seen it! The double roller cam chain had rubbed some chrome off the inside of the chromed timing cover! It was what it looked like, residual chrome rubbed off the inside of the $15 dollar stamped steel timing cover! I bought a $60 dollar cast aluminum cover that had plenty of clearance. It's been one thing after another with this truck! The motor is fine and runs like a top. I went ahead and built a 400 Turbo with a reverse pattern valve body in it, that lead to a Hurst Quarter Stick shifter. I deleted the fan and replaced the radiator with a 4 core and added two electric fans. That Clay Smith cam doesn't make any vacuum so I added a vacuum pump with a vacuum reserve tank. I had disconnected the rear brakes years ago for burnout contests and when I went to reconnect the lines I realized the rear brake reservoir had rusted and corroded and was no longer any good so new Master Cylinder, Prop Valve, all the brake lines, two rear wheel cylinders, and that's where I'm at now, doing a complete brake R&R...That dont include the scatter shield and the drive shaft safety hoops. I had to shorten the two piece drive shaft (front half) 1" inch and install 1350 u-joints with a 400TH slip joint. I installed an Autometer wide band O2 sensor and gauge to help dial the Holley 800 cfm in. I thought I'd have it ready last Spring but nope, these brakes are dealin me a fit. I plan on making it to the track before the snow flies but, but, but who knows. She did take a top ten trophy home last week at the local car show...

[scottofksu]

Beautiful truck and interesting thread! Just chiming in to say that, while you may be 100 miles from nowhere, you are slightly less than that from me! LOL
Glad to see another awesome Nebraska truck! I would love to drive down in my '65 once I get it put back together to see yours at a show or something .

[Average Joe]

So freakin cool you kept your power brakes! That’s too bad about the chrome timing cover but great info for everyone else. Thanks for the update and best of luck to you sir!

[Ironangel]

Originally Posted by scottofksu

Beautiful truck and interesting thread! Just chiming in to say that, while you may be 100 miles from nowhere, you are slightly less than that from me! LOL
Glad to see another awesome Nebraska truck! I would love to drive down in my '65 once I get it put back together to see yours at a show or something .

Maybe we can hook up at that track just south of Omaha, Pacific Junction? I'm still dealing with brake issues but should have her ready for some shake down runs soon...

Originally Posted by Average Joe

So freakin cool you kept your power brakes! That’s too bad about the chrome timing cover but great info for everyone else. Thanks for the update and best of luck to you sir!

Thanks Joe, I wound up having to replace all the brake lines, a work in progress...