Help Me Plan a Stroked Sleeper

[Roger D]

Before stumbling onto this forum I though perhaps I was a bit, "different" for wanting to build-up a Cad, rather than follow the crowd and re-build a bigblock Chevy/Mopar/Ford muscle car. Well, after spending some time here, and on MTS and CAD Co., I'm suddenly feeling almost normal.

The current plan is to purchase a very clean '68-'70 Coupe DeVille -and stroke it to 540 or so. I'd use it for a Sleeper street rod/muscle cruiser -with a few trips down the 1/4 during the summer - but it should be very "streetable" and run on 93 pump gas.

My goal is to increase the stock engine's already substantial low end torque - keeping the torque curve more or less flat between 1,600 and 4,500 rpms (but I'll gladly take 500 +/- hp if its not too high in the rpm range).

Right now I'm considering (but don't know enough to decide upon): intake, carb, cam (roller?), springs, rockers, etc. valves, crank (balancing worth it), rods .030/.040 over + 10:1 pistons, heads (ported/polished 76cc's? aluminum?), deck and flux the block? ignition, fuel pump, build the th400 and the big question - what to do about the 2.92 rearend (will an older 3.21 swap in)????

Any advice would be greatly appreciated.

Best regards,

Roger D

[DaveSmed]

Originally Posted by Roger D

Before stumbling onto this forum I though perhaps I was a bit, "different" for wanting to build-up a Cad, rather than follow the crowd and re-build a bigblock Chevy/Mopar/Ford muscle car. Well, after spending some time here, and on MTS and CAD Co., I'm suddenly feeling almost normal.

Now that's a scary thought, hanging around here makes you feel normal?!

The current plan is to purchase a very clean '68-'70 Coupe DeVille -and stroke it to 540 or so. I'd use it for a Sleeper street rod/muscle cruiser -with a few trips down the 1/4 during the summer - but it should be very "streetable" and run on 93 pump gas.

My goal is to increase the stock engine's already substantial low end torque - keeping the torque curve more or less flat between 1,600 and 4,500 rpms (but I'll gladly take 500 +/- hp if its not too high in the rpm range).

Right now I'm considering (but don't know enough to decide upon): intake, carb, cam (roller?), springs, rockers, etc. valves, crank (balancing worth it), rods .030/.040 over + 10:1 pistons, heads (ported/polished 76cc's? aluminum?), deck and flux the block? ignition, fuel pump, build the th400 and the big question - what to do about the 2.92 rearend (will an older 3.21 swap in)????

Intake is a very good choice. Once you get a good look at the lower plenum on the factory one, you'll see why. With the cam, you have to be careful. go too big, your going to need to re-engineer the vavetrain. This also applies if you intend to go above 4800 rpm. With the rear, see if you can get a commercial chassis/Fleetwood 75 rear, they had a 3.21:1 as opposed to a 2.94:1 ratio. An easy way to tell is as you look at the pinion flange, theres a small flat spot to the left towards the bottom. Look for a G-1. There pretty rare, so you might need to settle for a 1. The difference is the G means limited slip. 1 means 3.21:1, and 2 means 2.94:1. Also, consider a rear end swap, for greater parts availibility.


(If you happen to find two G-1s, let me know! )

Wow, 500 posts already?

[JWalker]

kinda depends on your budget for this engine.

if you really want a stroker i would advise you to be conservative as the amount of torque they produce will break things.

as far as the engine goes the sky is the limit with the aluminum heads
for what i think you want (limited rpms) a set of well ported closed chamber heads will work just fine.
you might as well go .060 over right off the bat as it doesnt hurt anything and you have plenty of meat left for rebuilds and reguardless of what people tell you if your cooling system is up to snuff you will not overheat.
A 4.40 stroke with the rod journals cut down to mopar size is the best option there is for a factory crankshaft.
that will give you a 525 inch engine
youll also want some longer 6.86/6.9 or so aftermarket H beam chrysler type connecting rods.
custom forged pistons are pretty much mandatory and there are many choices ,Ross being IMO the best around .
the heads wont be exactly cheap but youll need some air to feed it
if you want to run an edelbrock intake the one built for the cadillac will somewhat limit your horsepower production but it isnt as costly as an adapted ford intake .
you can make the power your after with a mild hydraulic camshaft and 9.5-1 compression.
the stock rocker arms are junk so get a non adjustable shaft setup from Rockerarm specialist
they have a couple different setups and the one that seems to be the best is a cast 1.7 ratio that is around $380 or so.
the cheaper stamped setup takes away too much rocker ratio but if your on a budget they are dead reliable.
the rest is pretty straight foreward
cloyes chain...mandatory
good melling pump

you will want headers and they arent that difficult to fabricate
Id go 2" but 1 7/8 will also work
ignition.....a rebuilt recurved HEI works great on the street and occasional strip ventures
hope that gets you started
good luck and happy car hunting

this engine will not be cheap and if you find it beyond your budget there are several other ways to lessen the cost of a big caddy and id more than willing to help you out
JWalker

[Roger D]

THANK YOU GENTLEMEN!!!! This project is going to be a great deal of fun.

DaveSmed - if I do come across an spare G1, I'll be sure and e-mail you.
JWalker - thanks for your offer of help and the great deal of detail you provided in your post.

As for the budget - one of the many benefits of building a Cad v. a Big Block Chevelle/GTO/442, Mopar, Mustang, etc. is the substantial money saved in the purchase of the vehicle - even for a solid "2". That leaves a lot of cash to build the engine, tranny, rearend, brakes; paint/etc. The budget for the engine build will be ok (but probably approach the price of a 502 crate engine).

So, back to the well with a few more questions:

Before even addressing a swap in of a 9" or 12 bolt rearend - will 3.42's or 3.55's provide much over the 3.21's for 1/4's and street rodding - and still be cruise friendly? One of the tech's at Currie told me it would not be an easy swap! (Initially I thought a 3.73 rearend w/ a Gear Vendors UD/OD behind the TH400 would be a slick setup.)

Does the Ford (adapted) manifold flow signficantly more than the Edelbrock Caddy set up and how complicated is it to do the adaptation?

Is it worth buying one of the proprietary "Stroker Kits" sold by MTS or Cad Co.? - It would seem buying a kit would be much more simple and cost effecient than assembling/machining the parts.

I'd be happy to keep the iron heads and have them polished/ported and the valves angled - but will the 76cc's on top of a 525 or 540 crank/rod/piston support 500 hp+/- and 650 torque - and should larger valves be dropped in?

Many thanks again and regards,


Roger D

[JWalker]

Originally Posted by Roger D

THANK YOU GENTLEMEN!!!! This project is going to be a great deal of fun.
Roger
enable your private messenging and or email me at
walkerz@bright.net for more information
thanks John Walker
DaveSmed - if I do come across an spare G1, I'll be sure and e-mail you.
JWalker - thanks for your offer of help and the great deal of detail you provided in your post.

As for the budget - one of the many benefits of building a Cad v. a Big Block Chevelle/GTO/442, Mopar, Mustang, etc. is the substantial money saved in the purchase of the vehicle - even for a solid "2". That leaves a lot of cash to build the engine, tranny, rearend, brakes; paint/etc. The budget for the engine build will be ok (but probably approach the price of a 502 crate engine).

So, back to the well with a few more questions:

Before even addressing a swap in of a 9" or 12 bolt rearend - will 3.42's or 3.55's provide much over the 3.21's for 1/4's and street rodding - and still be cruise friendly? One of the tech's at Currie told me it would not be an easy swap! (Initially I thought a 3.73 rearend w/ a Gear Vendors UD/OD behind the TH400 would be a slick setup.)

Does the Ford (adapted) manifold flow signficantly more than the Edelbrock Caddy set up and how complicated is it to do the adaptation?

Is it worth buying one of the proprietary "Stroker Kits" sold by MTS or Cad Co.? - It would seem buying a kit would be much more simple and cost effecient than assembling/machining the parts.

I'd be happy to keep the iron heads and have them polished/ported and the valves angled - but will the 76cc's on top of a 525 or 540 crank/rod/piston support 500 hp+/- and 650 torque - and should larger valves be dropped in?

Many thanks again and regards,


Roger D

[Caddy_freak]

I'll be paying close attention to this one, I've got a 500 out of a 76 that I want to rebuild for my 81 fleetwood, I was Thinking about MTS stroker kit. I know it's insane but....OH man it's tempting.. Just need to find me some 76cc heads.

[JWalker]

you wont want a 4.58 stroke in a cadillac(with a factory crankshaft)
the much smaller diameter and wider journal makes the crankshaft pretty weak
Best thing to do is build a 4.40 stroke with a mopar rod journal and go a little bigger on the bore.
additionally the longer stroke engines have a tendancy to kill the horsepower and make just a little bit more torque than a well built stock stroke 500
The iron heads will flow more than enough air for a bigger stroker engine but there are only a few people out there that can provide you with the kind of airflow youll need.
there are sets of heads out there with bigger than needed in both diameter and more importantly weight that have horrable both low lift and peak lift flow numbers touted as high performance...do not believe the claims they are making.
so yes the iron head will support quite a bit more than 500 horse and 650 torque but you have to be very careful about parts selection.
peak numbers mean nothing
you want power numbers thru the rpm range and that is gotten with good airflow(good low lift numbers (.300-.500 ) and proper cam selection
everything else you do is pretty simple
an engine this big will need a 2" header and something better than an edelbrock performer as they are nothing but an aluminum cork.
you dont want to run stock rocker arms,a simple non adjustable shaft system will at this power level do everything you need altho rollers make a little more power not worth the headache or pricetag.
I could go on and on but these are the things i know for sure work.
more info my email is here somewhere...JW

[caddyman529]

Originally Posted by Roger D

Before stumbling onto this forum I though perhaps I was a bit, "different" for wanting to build-up a Cad, rather than follow the crowd and re-build a bigblock Chevy/Mopar/Ford muscle car. Well, after spending some time here, and on MTS and CAD Co., I'm suddenly feeling almost normal.

The current plan is to purchase a very clean '68-'70 Coupe DeVille -and stroke it to 540 or so. I'd use it for a Sleeper street rod/muscle cruiser -with a few trips down the 1/4 during the summer - but it should be very "streetable" and run on 93 pump gas.

My goal is to increase the stock engine's already substantial low end torque - keeping the torque curve more or less flat between 1,600 and 4,500 rpms (but I'll gladly take 500 +/- hp if its not too high in the rpm range).

Right now I'm considering (but don't know enough to decide upon): intake, carb, cam (roller?), springs, rockers, etc. valves, crank (balancing worth it), rods .030/.040 over + 10:1 pistons, heads (ported/polished 76cc's? aluminum?), deck and flux the block? ignition, fuel pump, build the th400 and the big question - what to do about the 2.92 rearend (will an older 3.21 swap in)????

Any advice would be greatly appreciated.

Best regards,

Roger D

I've done what you are planning, but I put it into a 1949 caddy. You will be happy with the results.
go to http://photo.starblvd.net/caddyman529
I surprise alot of people with my old caddy.