BigDaddyJC

Hey, I'm an old codger. Not too up on the Google thingy. Dont think I know any Jason Mulkey either..... My dreams of a V8Z once again came crashing down yesterday evening when I went to look at the 86 Turbo Z and found that it had became the local neighborhood parts car..... Car is too trashed now to consider bringing back to life again. Back to my 86 RX7 Conversion now.......

I have a SBC solid front engine mount I designed for use in hybrid conversions. I am having the first prototypes ran this week. The material is 3/16" steel plate with 1/2" bends along all perimeters for added strength. Its a solid mount that bolts to the front of the engine at 8 places. I have pdf. file of the drawing, or could possibly offer up a complete kit for the engine and turbo 350 auto tranny, once I get mine all installed and bolted up. Since this is a swap that there seems to be limited info. and parts available, I just decided to design some up myself. I'll post up some pics of the engine mounts and spacer once its done and go from there. As of yet, I still have to complete the first install before I offer up anything though for sure. My mount locates itself up onto the frame rails instead of down on the lower cradle. I am still debating on whether to make it a solid mount or use factory GM mounts.

Yea, you are probably right, I was thinking about the engine when it had the Alum. closed chamber heads and roller cam setup......One can always dream though.... Whats Google...Not familiar with those gear ratio's......

I can probably buy another RX7 body with good title and just use my other one for spare parts, but I can also get the late 86 300ZX Turbo car for free with good title. The Z car has no rear seats since its not a 2+2, and the RX7's do have a back seat, so I am wondering exactly just how much weight difference there really is between these car bodies?

Considering a V8 Chevy swap into a late 86 Z Tubo body. Car still has all the factory stuff, and has T-tops. My engine for the project is a Chevy Small Block 400, 10.5:1 Compression Dome Top Pistons with 5.7" SBC 350 Rods-ARP bolts, with 76cc Chamber heads, cam setup to still run pump gas, high rise dual plane alum. intake, headers, 2500 rpm stall and Tubo 350 auto tranny. My setup will probably put about 400-450 ft. lbs of torque to the rear wheels. Questions I need help with: 1. Will the stock body and chasis handle the torque without weld in bracing and extra chasis work? 2. Will the late 86 to early 87 Turbo rear end handle the torque? 3. What should I expect the factory gear ratio to be on this car? 4. What will be my cars weight without driver if I drop the V8 chevy swap into the Z31 Turbo car? I am torn between using this car body to make a nice street/strip car or use a 86 RX7 N/A body. I know the RX7 body will weigh in at around 2880 lbs without driver, but I only can use it as a full time drag car cause its abandoned/no title rig. Anyone help me decide which way to go? I have custom designed a solid mount front engine cradle that will work in either swap, so I just need to get some input on what the Z31 is capable of with the Turbo rear end.

Well, lets shift gears here and try again. I just inspected the underside of my 81 2+2 and its officially now a basket case. Frame is rotted out on driver side from firewall back to behind the front seat. Passenger side is starting to show signs of rot around the area right past the firewall also. Frame on both sides is crushed from people trying to lift the car with the rails. After today, its now just a doner car for parts in my book. Its time to pull out my 73 240Z now and yank its stock motor/tranny to begin the V8 Conversion. Any help on total frame replacement and tube front ends would be greatly appreciated. My 240Z front frame sections has been clipped at the firewall at some point in time, so I want to go ahead and do this up right the first time. Eventually, this car may become a Drag Car, so I want to do what it will take to make it hold up to 450 to 500 HP if necessary. Excluding rear end swaps for now though cause my current engine setup is probably only going to get me around 300 HP. Probably still have a good bit of torque though, since it is a 400 small block. Links to pics, dimensions, drawings and stuff would be appreciated, along with any advice while doing this build. I will also probably go ahead and look at installing a cage also.

Well, after a short drive this afternoon to where the 81 280ZX is at, its plainly evident that its going to be the 73 240Z for sure now. I was leaning towards it anyways, but now after looking close at the underside of the 81 2+2, its plain that its days as a drivable car are over. Frame rail on driver side is bad rusted out and torn off all the way back to the rear of the driver seat from the firewall. After discovering this, its now just became a doner car for sure. 240Z all the way now baby. I may just go ahead and look towards replacing the whole frame and building a tube frame from the firewall forward. Might as well do this right the first time and not have any regrets.....

Figured this would be a good place to ask this question. Which of these two cars is the easiest and best one to set up with a 400 SBC and turbo 350 tranny? I have my choice of doing this build with either, so I need help making this decision. My 240Z is still all original with the factory engine and 4 speed tranny. Motor was supposedly running before I got the car, but right now its got some fuel/carb and firing issues. Brakes will need completely replaced with all new parts, Car has sat for a few years, and everthing in the brake system is froze up. This car has been wrecked, and the frame has had work done on it before-replaced from the firewall forward I think. My 280ZX 2+2 has a blown clutch. Never heard the engine run. Everything else seems to be in good shape. I have studied up on all the conversion postings, and from what I can tell, the 240Z would be my easiest Conversion project, and the lighter of the two cars for sure. But on the other hand, the 280ZX has the stronger rear end, and would probably have a better chasis to handle the 400's torque, plus some extra weight on the rear wheels to help traction. Which way should I go????

What did you have to do underneath your car? Any special subframe connectors and body stiffeners? I am just trying to find out if the stock ZX body will hold up to my 400 sbc setup without having to do a lot of stuff under the car. You can shoot me any pics you got of the setup of your car at JimmyC@Hired-Hand.com. I appreciate all the help you guys have offered me so far. It goes a long way to saving a lot of killed time when you got other people willing to help a guy out thats never done this type of swap before.

Probably going to make my own engine and tranny mounts. I plan to do all the work on my car myself, so I am going to style my tranny mount after the JTR mount brackets. No one has ever gave me a straight up answer on how these 280ZX car bodies do with the V8 swaps. Mine is a 2+2 hard top version and I am just trying to find out if there is any extra stuff you have to actually do to the underside, or if they will hold up to a 300 to 350HP engine without any frame rail or body pan reinforments?

Thanks guys for all your info. I plan to run the Turbo 350 though because I will be running it at the Drag Strip and just on Rural roads most of the time, so the low gear ratio is not going to bother me any. Plus its already built and the money is already invested in it. I do plan to build all my own mounts and stuff. I am really curious about how well the bodies hold up to the V8's. I am expecting to have to really beef up the underside of the car to prevent it from flexing and twisting. Is this been a problem on either or your cars, or are you both running the factory bodies without any extra subframe connections underneath?

New to the forum. Starting a new project with the following stuff. Need advice and any info. that would help me get this going. Car: 1973 240Z with 3.34 factory gear ratio-rear end. Engine: SBC 400 standard bore 2 bolt main block SBC 400 standard crank Sterling Dome Top Pistons-Hypeurectic 350 5.7 Rods/ARP bolts Edelbrock 750 carb Performer Air Gap Alum. Intake Double Roller Chain and Gears High Volume Oil Pump Alum. Water Pump Cam Style: Hydraulic flat tappet Basic Operating RPM Range: 2,500-6,800 RPM Intake Duration at 050 inch Lift: 232 Exhaust Duration at 050 inch Lift: 232 Duration at 050 inch Lift: 232 int./232 exh. Advertised Intake Duration: 280 Advertised Exhaust Duration: 280 Advertised Duration: 280 int./280 exh. Intake Valve Lift with Factory Rocker Arm Ratio: 0.485 in. Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.485 in. Valve Lift with Factory Rocker Arm Ratio: 0.485 int./0.485 exh. lift Lobe Separation (degrees): 106 Intake Valve Lash: 0.000 in. Exhaust Valve Lash: 0.000 in. Computer Controlled Compatible: No Grind Number: 280 Mega Will be running the cam with -4 deg. retard to help bleed off compression. 76cc Chamber Heads. Hooker block hugger headers Tranny: Turbo 350 with HD race clutches and shift kit. Stock converter. WIth all this listed, what can I expect to have to modify on the car to hold up to this engine/tranny setup? I want to keep it a streetable vehicle with good gripping street tires. Not really planning on running drag slicks on the car cause I want to try to keep the stock rear end under the car as long as possible. Any advice, or suggestions on the car body, suspension, frame modifications is greatly appreciated. I am going to be doing all this work myself. Jim C.