[h0trod389]

wassap folks!

i just picked up a 63 389 with head # 543797's for my 1930 olds.

i had a few questions about this build.

my plans are using the 4.25" eagle crank. when i bought this crank i also purchased the 6.800 BBC H-beams.

everyone is tellin me to run later style heads, but i want to utilize a old hilborn injection unit for early pontiac.

i know that these heads are closed chamber and i prolly wont beable to use these 6.8's with these heads.

should i run a standard length rod for this application?

or should i build a 400 instead with a set of 6x-4's, and a adapter plate for the hilborn?

last question, the bell housing bolts are 7/16" instead of the regular 3/8" bolts, was this common? or did someone drill and retap?


last time at the track i ran a junkyard 400, lost compression in #5 and still laid down a 13.3 @ 104

i want to reach atleast high 10's!

P.S. THE SHEET METAL HAS BEEN REPAIRD ALREADY..hahaha

[PONTIAC LARRY]

Whatever tranny you had behind the 400 , won't line up with the 63 block, different bolt pattern and starter bolts to tranny too.. An adapter is commonly used to put the later tranny to the older block and it has provisions for the starter..You would be better off with the 6X-4's and the 400 block by far... A 2.11/1.66 valves or 1.88/1.6 Yuck..and 9.6:1 with 6x-4's vs 11.5-12:1 if using 389 heads and flattops.. eek.. 461 cubes rock in a 400 block though..its a 447 cubes in a 030 over 389. Cool Rat Rod !

[fasteddy]

7/16s are original on the 63s 4 cylinders and V-8s bell housings.

[h0trod389]

well.....

i like the sound of more compression! but your right, the valves are wayyy too small!

my main goal for this engine is to run the hilborn set up.. i know, i know, one shouldnt build a engine off a induction set up, but theres nothing fuggin cooler than a hilborn!

i take it that making adapter plates from the 65-77 style of head to the hilborn is my best option.

if so, then i can use a diffrent set of heads for more compression.
i havnt bought pistons yet due to the uncertiny of which direction im going.

a few more questions....
using a 400 block,
what pistons are avaliable for this build, in dish and dome form?
i have heads from 114 cc's to 72cc's
i will be porting the heads i use, along with filling in the heat crossover with zinc.
how much clearence grinding will i need to do on the block itself to make this 4.25" stroke crank fit?

thanks for all your help!
Brian

BWT... its a hotrod in progress not a ratrod
this is how she started out!

[Brian Baker]

Egad, that thing wasn't even a "shell" when you started.

If going the 400 block route, and you want to keep it on pump gas, a head of 86cc-96cc would be what you want to go after. The 6X-8 head will usually come in around 96cc if it hasn't been cut on. They come with 2.11/1.66 valves. If you don't mind running a little race gas mix, go with the 72cc heads and order the pistons for whatever bore you're running...only thing left to figure out is the compression height on them for use with the 4.25" crank and 6.8" rods. Regardless of head, you'll want a falt-top, unless you're bent on using the 114cc head and need to bump up the compression. There are many Pontiac vendors that frequent this board that can help with the pistons...for the money, I like BRC.

Making billet adapters for the Hilborn to mount to the newer heads will be a piece of cake, and you can beadblast the sides of the adapters for a cast appearance.

[h0trod389]

i dont mind runing higher octane fuel. hopefully in the future, i can convert to corn fuel.
but i have to wait for the government to pull their heads out of their rectums for that.

altho i have a set of 4x's in stock, im not set on using em.
but either a set of 62's or 16's should fit the bill nicely.
with some pocket porting and
exh. block off work done to em, sounds like its my ticket!

i occasionally drive this rig on the street, but mostly for track use.
id go aluminum, but edeljunk's are above my paygrade!

thanx for all your info!
heres a short vid of me messin around!
take care guys, and hopefully ill see you @ the x-mas tree
http://www.youtube.com/watch?v=1LTcm...e=channel_page

[Brian Baker]

Use the 16's or 62's and let the Cam-2 Purple or VP Red flow.

[BruceWilkie]

pattern t400 adapter attached. 63 IS same bolt pattern but block has no provision for a starter. This adapter solves that.


4x heads are generally same as 6x. Some had screw in studs some didnt. like 6x heads most will give @ 8:1 compression on a 400 unless you mill them. However if you put a stroker crank in there compression will increase to the 9.2-9.7 range possibly more it depends on cubes and piston deck height etc.

[andyleonard]

I'm making the same choices with a '63 block, early Hillborn setup and either 797 or #13 heads. Clearly the heads have to be chosen before the pistons are purchased - adapting the Hilborn to the later heads can be done and shouldn't influence the deal - and the choice for me seems to be determined by CFM and how "old school" you want to be. I have "date of manufacture" issues in my class.

So, here's what Knowlegable People have tried to explain to me so far: if you choose to use CFM numbers as advance notice of horsepower (whether you do or not is a separate thread) and assuming your choice is determined by horsepower (and not by some mysterious combination of smaller unshrouded valves and a good cam resulting in superior response for roadracing) , you seem to come up with this: if you port the smaller-valved 797s and get it really right, you might get 225CFM. If you flow the right 2.11 heads, you might get 265-275 CFM.

I would appreciate some expert feedback on this topic other than "get aluminum heads."

Thanks.

[Mr. P-Body]

It isn't a major deal to modify the flanges on the injector manifolds to "fit" the later head pattern. Most of the bolts already "line up" and some port work is called for anyway.

Rod length has nothing to do with what compression or chamber you use. It affects the pin height (compression distance) in the piston. If using BRCs or other "custom" pistons, all this is figured "in". We've used BRCs in several applicatoins where a fairly large "dish" is required, and they're excellent.

As for the D-ports, if porting, they're virtually all the "same". The chamber volume is the only significant difference between all the "large valve" heads. 12s have a slight "edge" when it comes to exhaust flow, but intake flow is within about 3% on ALL of the 12 degree large valve heads.

The Hilborne system is cool, alright, and can STILL "make power". I like the street rod approach! More of them need to wear "Arrowheads".

Jim

[andyleonard]

To clarify, the choice is between "old" 389 heads and the newer "all the same" 400 heads.

[Mr. P-Body]

To further clarify, I was refering to pre-65 389 heads and the intake flange. We've seen many "converted" to fit the later ('65-newer) flange.

Jim

[PONTIAC LARRY]

If you want the all vintage look with all early engine parts , 250 cfm should be achievable with a 2.02" SBC intake valve added to 63 heads with moderate porting..I think they fit ok?? Keeping the 389 style valve covers would look cool too.. +.060 bore + 4.25 crank 453 cubes , 11.75:1 and a Ram Air IV cam.. low .469" lift with 1.5's and the Hillborns ...Stout !

[andyleonard]

From Dave today at SD Performance:

"Your old heads aren't going to flow 250cfm and 2.02" valves will not fit either. I will be able to get them to flow 230-240cfm with a 1.94" intake valve and they have been great performers in the past but you are never going to make the early heads perform as well as the later big valve heads."

[PONTIAC LARRY]

Originally Posted by andyleonard

From Dave today at SD Performance:

I will be able to get them to flow 230-240cfm with a 1.94" intake valve and they have been great performers in the past but you are never going to make the early heads perform as well as the later big valve heads."

I not debating that the big valves (regular) heads will flow more...Duh !

It was "if" he want's to remain with a "all vintage parts look".... 230 cfm is adequate to deliver the HP/TQ to move that 2000 lb Go Cart into the Tens.. I magine a simple 450hp/550ftlb combo could be had with the above mentioned combo (453 stroker cubes, 11.75:1 389 heads/block, 235 cfm 1.94/1.6 valves)

but a 400 block and #16's would be easier...