i have an 87 2.8 v6 camaro and was wondering what v8 would be the best to swap it with. Would i have to change the tranny for that kind of swap?

 

Yes, you will need to change the transmission. You'll also need a ton of other parts, like front springs, a radiator, dash gauges, motor mounts and a crossmember to name a few.

 

You can reuse your dash guages. I did with my 85 firebird with a 2.8 when I swaped in a 327 from a 65 vette. It worked fine and with a wire diagram I was able to hook it up. The V-6 tach worked accuratly as well with the v-8and it shows a higher RPM than the v-8 tachs so that was better. It was carburated so I didnt need a computer or emmissions. Yeah you will need a new bell housing because the bolt patterns are not the same. If its a manual I think you can re-use the tranny but not the bell housing, they do seperate. The auto tranny has a one piece tranny-bellhousing. You will need new front springs but the rear are the same. The engine crossmember has holes drilled into it for mount the 4, 6 and 8 cyclinder engines, so all you will need is different engine mounts. The radiator is a little different but you might get away with the 6 cyclinder radiator for a little while. The upper radiator mount is different (a few inches longer) The tranny mount should be the same as well as the drive shaft unless you use a different tranny. I did so I had to get a new driveshaft and had a custom mount cross memeber made for my 4 speed muncie and later 6 speed richmond. You will have to reroute the fuel lines or replace them. If its a manual tranny then you need a different clutch fork. Oh and depending on what intake and carb or fuel injection you use you have to be careful of hood clearance. I had to use a 2 1/2 inch cowl hood to clear my weiand intake with carter carb and edelbrock triangle filter.... later I put a 1 inch spacer but still fit. Before the one inch spacer and regular hood the top of the filter contacted the bottom of the hood. It wouldn't close with the insulation so I had to cut that away. If I can think of anything else I will let you know. ~ Erik

 

The V6 Tachometer will absolutely not read accurately on a V8. It might "work", but it will read 25% too high.

I've done this swap. I swapped a 350 into my old 1986 2.8 Camaro.

You will also need a 60lb oil pressure sender to go with the 60lb gauge integrated in the V8 Tachometer. You'll want to find a 155 mph speedometer too, and dump that 85mph POS. I'd recommend getting an entire gauge cluster from a late 80s Iroc with a 155 mph speedo.

The V6 uses a 80lb oil pressure gauge and sender if your V6 car has the optional gauge package. I've seen many V6 cars that have a speedometer and fuel gauge only, with no other gauges.

If you run a carb and a HEI you wont need many wires under the hood.

1) Tach lead
2) +IGN at HEI
3) Temp sender
4) Oil pressure sender
5) +IGN at alternator

 

Actually your V-6 tachometer will work accuratly with a V-8 depending on how it reads your engine speed. Mine worked accuratly when I swapped from the v-6 to the v-8. When it does matter between V-6 and V-8 tach is when you use a points distributor. This is because the tach counts the number or pulses by the cyclinders hence the V-8 has 25% more pulses and the V-6 tach will think your RPMs are higher than they really are. Your V-6 engine does not use points and is a computer controlled distributor. When I switched mine from a V-6 to a V-8 I used a Mallory unilite distributor which does not use points either, it uses fiberoptics which are much more accurate and never need to be messed with like points do. I connected my tach wire to this distributor and my tach was very accurate. It idled just like it was supposed to and was dead on all the way through the RPM band. So your v-6 tach will work as long as you dont use a old points distibutor, which are so outdated you wouldnt want to use one anyways. You might want to get a new instrument cluster anyways because of the 85 mph speedometer but if you can live with that I see no reason to get a new one. Oh and if you keep the old cluster you can reuse your 80lbs oil sender. With mine I just need an adapter to make the metric threads fit in a standard thread hole.

 

I used a 1975 HEI coil-incap distributor and mine didnt read accurately. It had an Accell Ignition Module in it and an Accell SuperCoil on top of it. It did not have any points in it. All tachometers use the same pulsed input. They all work off pulses, and a V8 will put out 25% more pulses than a V6.

How did you know for sure yours was accurate? Did you ever install a V8 tachometer and compare the readings?

The ECM on the V6 car does not convert the 6-pulse to an 8-pulse and send it to a tachometer configured for a V8. The pulses from the V6 ignition goes directly to the V6 tach from the coilpack.

Also, the circuit board on the back of the tach is labeled either V6 or V8 and you can actually swap just this circuit board if you really want to keep your original gauges and have them read properly. Then you could re-use the 80psi oil pressure sender too.

All he really needs is a beat up gauge package from any pre-90 3rd gen V8 car with a tachometer that works. Once he has that, he can swap the circuit board from the tach into his cluster and his will read accurately.