Autocomman,
I've followed your thread as it is not unlike my own build (starting point is a 250-powerglide-3.08 Nova 63ss).
So I am starting with a tad more gear and almost 300 lb less weight, but otherwise similar.
I agree with all the suggestions so far (and the order), whether you do the trans and gear first or last is of course up to you, but I agree with these guys it is the best single mod you could make (the 200-4r trans). That said, I too am doing things in the reverse order (engine first, then trans/rear). I suppose what triggered my order was, my 292cid was sitting outside and got rained on once, so my goal was to get it back under the hood.
With that I will use my Gonkulator computer (take it with a grain of salt but it's easier than wrenching....) to show how your car might proceed so you can put some numbers to "ok" vs "quick" vs "fast".
Here is what the Gonkulator thinks you have now.
Stock 250/155
3.03 60ft
12.77 at 58.7mph 1/8 mile
19.57 at 71.0 1/4 mile
For comparison, Motor Trend tested a 69 Nova 250/155, th350 trans, 3.08 rear. With 2 people aboard they got
19.00 at 71.0 1/4 mile
Well, if you think that is "ok", have we got good news for you.
The single most effective mod you could make under the hood would be to swap the 250 for a stock 292:
2.88
12.06 at 61.0
18.63 at 73.8
However, more effective than that even is to leave your stock 250 there and swap in a 200-4r trans:
2.60
11.58 at 59.4
18.23 at 72.9
That is a 1.3 sec change in 1/4 mile from a single mod. Wow.
Add a 3.55 gear (give or take) for
2.48
11.31 at 59.7
17.98 at 73.0
This is still your bone stock 250 and dinky stock exhaust!
OK, what if you do the engine first?
I computed the engine described by Hank MBHD - and a selection of four intake systems:
Offy-4bbl and Carter/Edel AFB 500cfm on top
Clifford-4v and Carter/Edel AFB 500cfm on top
Offy-3*1bbl and 3 Roch BV carbs on top
Offy-2*1bbl and 2 truck 292 Roch B carbs on top
All four of these 254cid ~9.5 compression combos gave the same result within about a tenth and 1mph or so:
Torq 280 at 3500 give or take a few
Powr 240 at 5200 give or take a few
2.85
11.70 at 67-ish
17.40 at 85-ish
Now adding the 200-4r and 3.55 gears, again all the intakes did about the same within a tenth and a mph or so
2.35
9.90 at 72-ish
15.45 at 87-ish
As you can see, even moreso with the built engine, the 200-4r and gear added the most - nearly a 2 second improvement. They are a must-do - and you now have a car that is quicker than many factory 327 Novas and even a few factory GTO's.
So that is the story, many of us (me) kinda have to use 1/4 mile numbers to describe what "ok" vs "fast" vs "bow-wow" is. Hope this helps.
