: Torque, 700r4, tbi, specs and more noob questions

06-21-04, 02:39 AM
hello everyone i bought a 76 edlo convertable just purely for the motor, and need all the help i can get, heres the rundown, i have a 1989 full size chevy blazer for offroading, but it is way underpowered, and due to smog in ca, i cant beef it up too much, so i bought a 73 gmc jimmy and a 500 cid for it, heres my goal
Torque!!! with TBI for the extreme angles i'll be running offroad. my plans so far (now i dont know anything about caddys yet so bare with me)

500 stroker?
tbi setup
700r4 tranny rated to 650HP(http://www.fearthemonster.com/transmissions/megamonster/heavyduty/700r4/)
203 or 205 transfercase

anyway in short i need pointers on how to acheve maximum torque and the lowest RPM range possible with TBI

BTW i read this from a link here and dont know if its true, does my 76 make this much power?
" The 500 is rated at 190HP@4000rpm and 380tq@2000, but that's underrated. It actually has >300hp and >460tq bone stock. "

lux hauler
06-21-04, 05:08 AM
Any particular reason for going with the 700R4?

06-21-04, 11:19 AM
i just thought it might be a little cheaper than a 4l80e, am i wrong?

lux hauler
06-21-04, 01:14 PM
Any particular reason for wanting an overdrive trans?

The 4L80E is a much stronger tranny than the 700R4. The 4L80E and the 700R4 are both Chevy bolt patterns......you'll need an adapter to bolt the big Caddy to it (these Cadillac engines have the BOP......Buick, Olds, Pontiac...bolt pattern).

If this is going to be used just for off road, why not just use a 400 trans and save some money and work? TH-400 transmissions with the BOP bolt pattern should be pretty easy to find and will stand up to the torque of the engine with no problem.

06-21-04, 02:25 PM
i wanted the OD because i have 5.13 gears now and 37 inch tires that weigh about 120 each with the rims. and i dont have a trailer yet, so i'll be driving the freeway to any offroad location.

i believe the caddy i have came with the 400 right?

lux hauler
06-21-04, 03:23 PM
These engines produce alot of torque at low RPM's. Whether or not a 700R4, under these conditions, will live, I can't say. I have read ( www.bowtieoverdrives.com (http://www.bowtieoverdrives.com) ) that a properly built and installed 700R4 will live in a medium size car that runs 10 second quarter mile times.
I would suggest contacting a competent tranny builder (preferably someone who specializes in 700R4's) and telling them what you want to do to see what they recommend.

Did your engine come out of an Eldorado? If so, it's a front wheel drive car and used a TH-425 trans which has the same basic internal parts as a TH-400. The 70's RWD Caddys did have the TH-400 though.

06-29-04, 03:43 PM
Maybe I was looking in the wrong places, but when I was checking out beefed up 700r4s for my Cad 500 4x4 project, I found that the aftermarket 700r4 vendors knew about steet rods, pony cars and such but didn't have much experience with big block Cads and four-wheeling. I agree with Lux that you would be better off with the TH400 (it will live behind the big Cad). Also, go with a big RV style external trans cooler too.

My truck weighs almost 6k#, 37" tires, 4.89 gears, and the 1 to 1 final ratio in the TH400 and it will cruise comfortably at 60-65 mph no problem. IMHO, a true off-road capable truck, with large agressive tires becomes unstable at much higher speeds (granted, I have never burned up the highway in an H2!) If you do go with the TH400, look for a t-case with 4-to-1 or so low range, as the first gear in the TH400 is not very low. I have about 2 to 1 in my NP200 so I am on the brakes on the technical down-hill.

Torque in a 4x4 Cad? My notion is that the big Cad is inherently torque' and with the cubes you don't need to go with strokers, etc. When I am 20 miles out in the sticks, my desire is for reliablity and cool running, not max power, so I built my engine accordingly. Hi-flo water pump, shaft rockers, Edlebrock intake, and headers, not so big cam, all new electrics, filters, belts, pumps, etc.

06-30-04, 01:38 AM
wow, cool, thanks for all the help:) i e-mailed bowtieoverdrive last week and havent gotten a reply. i'd really like the 700 not only for the OD but also for the 3.06 first gear, plus the shop is somewhat local so i could pick it up. i hate to ask for advice and not take it, so what i'll do is drive my k5 as it is now, with a 1:1 final ratio and see how well it cruses on the freeway, if the speeds are doable, then i will look into the 400,

my crawl ratio with a doubler and a 700 would be:
Underdrive: 1.98 x First gear: 3.06 x T-case low: 2.01 x Differential: 5.13 x Final Drive: 62.47

and with the 400 and a doubler:
Underdrive: 1.98 x undefined 2.01 x T-case low: 2.01 x Differential: 5.13 x Final Drive: 41.04

thats a large difference, with my current crawl ratio of 43 i was really wanting more, but that was with a tired 350 putting out 250 or so TQ, so i dont know if a crawl ratio of only 41 will make me happy or if i need to step up to the 700r4... decisions decisions. Anyrate i'll see what type of warrenty they offer, and if they have a 1 year warranty i'll take them up on it and hopefully i wont need to use it