[rkraczek]

Hi all,

I recently acquired a disassembled 1968 400 with #16 big valve heads. Still has a standard bore with a slight .002 ridge at the top of each bore. Heads look good, to the point I can probably get by with lapping the valves and adding new springs and seals. Stock rods and pistons came with it as well as the crank, which has been cut .010 on mains and rods.

The goal is to put this behind a th350 with 3.36 gears, currently has a 2000 stall. The car is a'71 Lemans convertible, and will remain a street cruiser. I drive this car sometimes 300 miles in a weekend on the highway and in town, but I'm not afraid of stop light heroics.

I will be adding an overdrive trans at some point. I have a 200r4 to build, but may do a 4l80 instead,

Should I use these heads? I calculate about 9.7:1 IF it stays stock bore. Not afraid of buying Aluminum heads.
What roller cam size range would work? Custom grind or off the self? No more flat tappets for me.
Pistons will be replaced, forged or is cast ok?
I plan on buying Ramair restorations cast manifolds and exhaust system for a factory look, but not afraid of long tubes.

I don't have a 1/4 mile goal, just want to make a great low maintenance engine that has decent HP and Torque. How about 350+ HP and 400+ torque at the crank? Any advice is welcome.

I currently have an excellent running .030 over 350 I rebuilt about 17 years ago in it. Low compression #94 heads, '71 intake and '79 800 cfm Q-jet tuned for the 350. Runs great, but its no powerhouse.

[steve25]

That motor stock was rated at 350 gross hp and if you don’t set and post up a hp goal you would like now then you might be twisted by others here into buying Aluminum heads when you should be dumping as much money as you can into the short block build.

You can always down the road swap heads out in a afternoons work!

[rkraczek]

Good point, Steve. Edited my post. I'm at sea level and want to run this engine on 93 octane E10 pump gas.

[rkraczek]

Originally Posted by steve25

That motor stock was rated at 350 gross hp and if you don’t set and post up a hp goal you would like now then you might be twisted by others here into buying Aluminum heads when you should be dumping as much money as you can into the short block build.

You can always down the road swap heads out in a afternoons work!

My back remembers the last time I swapped those cast iron heads for another set! Almost worth the 2500 bucks for the aluminum heads just for the savings in chiropractor bills. I'm now spoiled working on my LS2

[tom s]

If me I would get everything measured,KNOW the numbers and order(if necessary)custom pistons to get you too the 9.5 or less CR and be able to pull into any gas station.Many dont have time to do it right but find the time(and money)to do it over.JMHO,Tom

[67Fbird]

need 2 things with every build...
GOAL
and
BUDGET

many folks on here can build you a 700 hp 400 cid engine......several can build you something that runs for $1500......without a posted GOAL and the BUDGET to achieve it with....might be a long thread

[OCMDGTO]

First off I wouldn't hesitate to run a HFT cam. As stated, you should give hp goals and budget.
That being said, I'm guessing you're looking for 400/425 hp which is a really nice street car that doesn't require major upgrades to the drivetrain, exhaust, and fuel system.
My old engine and current spare:
400 block .030 over with stock crank, Eagle rods, Speed Pro coated pistons, #16 heads(unported but gasket matched), 750 Holley, Torker 2 intake, Comp Cams HR288(236/242d, .520/.540L). 9.5-1 compression, RARE manifolds w 2.5" exhaust
I put 30k miles on it and it went 12.90s@3950lbs. VERY good street engine that I drove year round and I used a 3500 stall converter

[rkraczek]

Originally Posted by 67Fbird

need 2 things with every build...
GOAL
and
BUDGET

many folks on here can build you a 700 hp 400 cid engine......several can build you something that runs for $1500......without a posted GOAL and the BUDGET to achieve it with....might be a long thread

Ya, I was a bit vague.
BUDGET is 4k or less.
I posted my GOALS in my edited first post. 350 crank HP and 400 crank TQ on pump 93 octane. I will be assembling the engine myself. 13.5 quarter with 3.336 or 3.55 gears. Nice street manners with A/C on and an idle that doesn't shake the mirrors off.

[67Fbird]

You will want a full evaluation of the heads. How are the guides? A quick lap on the seats is NOT really going to cut it....using 50 yr old stock valves is NOT a good idea either. So keeping the iron heads becomes almost ....ALMOST useless. Valves = $230, k-liner the guides = $100, real valve job = $200 , cut n clean =$150 and springs/assembly = $200., cut for seals and keeper clearance, new keepers/locks ...So you are into iron heads for almost $1000. With NO PORT IMPROVEMENTS (at 400 hp you either need SOME port work or...lumpy cam which requires RPM ..which MAY need more than 3.55 gear) OR $2500 bolt on alum heads...DONE

You need to cc the heads to determine your pistons as you will want to zero deck the block to achieve the proper quench height which should be .040 +/- .005 (which translates to 0.000 +/-.005 deck height using the common felpro head gasket @ .039")


MONEY WELL SPENT:
Block prep. clean, deck, bore, line hone. BAM $1500
rebuild kit with Forged 14CC pistons $1100
cam n lifter $400

At 4k $$$ AND you want a roller cam....your going to have to cheat or be lucky somewhere as a retrofit roller cam and lifter is $850 then you still need pushrods and POSSIBLE machine work to the heads for the springs.

[TCSGTO]

Originally Posted by 67Fbird

You will want a full evaluation of the heads. How are the guides? A quick lap on the seats is NOT really going to cut it....using 50 yr old stock valves is NOT a good idea either. So keeping the iron heads becomes almost ....ALMOST useless. Valves = $230, k-liner the guides = $100, real valve job = $200 , cut n clean =$150 and springs/assembly = $200., cut for seals and keeper clearance, new keepers/locks ...So you are into iron heads for almost $1000. With NO PORT IMPROVEMENTS (at 400 hp you either need SOME port work or...lumpy cam which requires RPM ..which MAY need more than 3.55 gear) OR $2500 bolt on alum heads...DONE

You need to cc the heads to determine your pistons as you will want to zero deck the block to achieve the proper quench height which should be .040 +/- .005 (which translates to 0.000 +/-.005 deck height using the common felpro head gasket @ .039")


MONEY WELL SPENT:
Block prep. clean, deck, bore, line hone. BAM $1500
rebuild kit with Forged 14CC pistons $1100
cam n lifter $400

At 4k $$$ AND you want a roller cam....your going to have to cheat or be lucky somewhere as a retrofit roller cam and lifter is $850 then you still need pushrods and POSSIBLE machine work to the heads for the springs.

Spot on advise for the OP’s goals and budget. To run 13’s a good, solid stock type rebuild and mild cam will do it easily. I ran mid 13’s on real street tires and very low 13’s on slicks @3900# with stock #16 dport heads on a 400, cast iron intake and exhaust, 3.55 gears with a 2500 stall and a Crane 222/234 HFT. Best part was it could be driven anywhere in 20 or 100 degree weather. No trick parts or machine work are needed except lots of tuning and attention to detail.