snomobeelr Posted November 29, 2018 Posted November 29, 2018 After years of thinking about an overdrive and which one to get I opted for the Gear Vendor. I always had a TH-400 in the car and I always liked it. Only reason I wanted an Overdrive is when I am driving the car and going 55 or faster it's loud and I don't like her taching up for a long period of time. So here are some things if your interested in the install and how it has gone so far. The install is not as straight forward as I thought. Just more wiring than I realized. Nothing bad I also bought a G-Force cross-member that is "Supposed" to be made for the TH-400 and the gear Vendor unit - Model: RCAE-GV I have read so many posts about the trouble with the GV fitting and the Tunnel having to be Massaged or cut to get the unit to fit. I did not have to do that. No adjustments made to tunnel, don’t know if it is because of the G-force cross member I bought. . - Removed Driveshaft - Took off Tail of transmission. - Placed jack under trans and Removed the Stock cross member. - Installed the G/V adapter and just snugged mounting bolts. - Then installed new cross member and trans mount for test fitment. - Used templates provided by G/V (Paper cut outs we transferred to cardboard) to check clearance in tunnel. No issue not needing any massaging or cutting.. - Input shaft extension in adapter – checked clearance and added appropriate shims. ( Didn’t Know about this – sounds worse that it was) - Installed the G/V unit and it fit and bolted in without any trouble. Just a little hard to get to bolts on top. - There are two LED’s red and green along with a thumb switch to turn the drive on and off you need to install in the car . - There is also the Shifting Switch , just like the Headlight - bright switch but taller that gets installed. Still need to wire the Module and get the driveshaft length figured out. I wont be able to use the X-pipe any longer.. Her are some pics 6 Quote
MCfan Posted November 30, 2018 Posted November 30, 2018 Looks great and sounds exciting, Alan - nice work! I love projects that increase the versatility, performance and enjoyment of first gen Montes without messing with their classic beauty. Hope you are able to wrap up this worthwhile project without major hitches. You probably won't be testing it out until spring anyway, so no major time pressure. Thanks for sharing - keep us posted. 3 Quote
502ci Posted November 30, 2018 Posted November 30, 2018 Great choice. I have one on my Monte...502ci, TH400, Gear Vendors, and finally a 12 bolt with a Eaton Posi with 4.11 gears. What gears are you running? 1 Quote
Monteman1971 Posted November 30, 2018 Posted November 30, 2018 Thanks for the write up. Looks great!! Can't wait to see how it functions. What rear gear are you running and I'll be curious to see how much the RPM's drop. How much horsepower can that unit handle? Steve 1 Quote
Paul Bell Posted December 1, 2018 Posted December 1, 2018 I was just thinking of this last week, thanks for posting. I wasn't able to find any info about cross member fitment-you've answered that. I'm curious, what's the difference between the stock and GV specific crossmember/ Will a stock crossmember work? Quote
snomobeelr Posted December 1, 2018 Author Posted December 1, 2018 Hello , Glad I can post something that is useful to others. Wont be testing until next spring like you said 😕 I am running a 12 bolt 3.73 They say the Gear Vendor handles up to 1200 horse. Not that I am close to that. The stock crossmember will work from what they say but you have to modify it. I stole a picture from chevelles.com I do not know if this is the exact mod that needs to be done.. Quote
Paul Bell Posted December 1, 2018 Posted December 1, 2018 That's great to know. Looks like my lightweight tubular cross member from Lemon's Headers will clear it. 1 Quote
502ci Posted December 2, 2018 Posted December 2, 2018 Been so long since I installed mine but I used the stock cross member and used a sledge hammer to dimple some areas. Also I may have even spun it around backwards. I would have loved if they made an aftermarket one back then, it would have been much easier. Quote
snomobeelr Posted December 3, 2018 Author Posted December 3, 2018 That G-force Cross-member was worth it to me. I did have to drill the cross member bolt holes bigger for the supplied bolts. The instructions did say you could use the stock size if you used grade 8 bolts. The other thing with the G-force cross member is it is Heavy. I believe 45 lbs. It is fine for me but probably not for someone looking to shed pounds on their car. Here are a couple pictures. This is where I mounted the Switch and the LED's. But I have a NON-AC car. Quote
bigscaht Posted May 9, 2019 Posted May 9, 2019 On 11/30/2018 at 5:19 PM, Paul Bell said: I was just thinking of this last week, thanks for posting. I wasn't able to find any info about cross member fitment-you've answered that. I'm curious, what's the difference between the stock and GV specific crossmember/ Will a stock crossmember work? yes a stock cross member will work..i installed a gv on my 72 monte behind a th350/350 combo and used the stock cross member Quote
Tony D Posted March 24, 2024 Posted March 24, 2024 70 Monte with a Dart 427 SBC 525HP/510TQ T-400 + GV OD. G-FORCE CROSSMEMBER. 12 BOLT REAR 3:73 GEARS. 4 Quote
cny first gen 71 Posted March 24, 2024 Posted March 24, 2024 We have a couple guys with dart motors one is a 427 sb the other is a 434 sb both very nice. 1 Quote
Dtret Posted March 24, 2024 Posted March 24, 2024 2 hours ago, Tony D said: 70 Monte with a Dart 427 SBC 525HP/510TQ T-400 + GV OD. G-FORCE CROSSMEMBER. 12 BOLT REAR 3:73 GEARS. Welcome to the club. That’s one heck of a setup. Send us some pictures. We love pictures. 1 Quote
Paul Bell Posted March 24, 2024 Posted March 24, 2024 3 hours ago, Tony D said: 70 Monte with a Dart 427 SBC 525HP/510TQ T-400 + GV OD. G-FORCE CROSSMEMBER. 12 BOLT REAR 3:73 GEARS. Hey Tony, what is your engine RPM at 60 MPH with the GV overdrive engaged? Quote
Tony D Posted March 8 Posted March 8 GV engaged: RPM @ 60 is about 2200 RPM @ 70 is about 2800 W/O the OV engaged: RPM @ 60 IS 2800 AND 70 MPH AT 3300. Quote
Chevy Dave Posted March 8 Posted March 8 This sounds good if you have low geared rear axle. My 70 SS 454 has the standard 2.56 axle ratio and runs about 2000 rpm at 60 mph. This would not benefit me. I am curious what this setup costs? 2 Quote
bob 71 Posted March 8 Posted March 8 how long is the housing between back of trans to front of overdrive gear unit? Quote
bob 71 Posted March 8 Posted March 8 did GV say to use that crossmember or is it something you did on your own? Quote
Tony D Posted March 9 Posted March 9 8 hours ago, bob 71 said: did GV say to use that crossmember or is it something you did on your own? GV had recommended G-Force Crossmember for added frame strength, ease of installation and more clearance for larger exhaust. Quote
bob 71 Posted March 9 Posted March 9 im glad it worked out for you. i had nothing but problems. tech support wasnt very good Quote
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