Engine swap worth it?
Thread Starter
Cruising
Joined: Dec 2006
Posts: 13
Likes: 0
From: Montreal Quebec
Engine swap worth it?
I have a first gen SBC built to around 400 bhp. I also have an m21 close ratio which I may or may not choose to use. I have been trying to figure out the "best" car for my engine. I am aware that "best" is very subjective, but I am looking for a car where the install will be relatively quick and simple. I have considered the following three possibilities. Please feel free to propose others. The car must be a manual shift.
1)1985-1992 C4
2)Third gen F-body (weak T5 and diff)
3)1983-1987 442 (I know the chassis s*cks, but they are full frame and I have always liked the appearance of these cars. But again, sh*tty brakes, suspension, etc. At least they have an 8.5" diff. Probably more work for the swap.)
I can spend upto $10k, and I guess I have somewhat decided on a C4. I have seen a few in Autotrader that seem decent. I don't need a show car. My question is, if I get a C4 with the L98 engine, would I gain alot, performance wise, by swapping in my engine?
p.s. sorry about my "simple" profile, still working on it.
1)1985-1992 C4
2)Third gen F-body (weak T5 and diff)
3)1983-1987 442 (I know the chassis s*cks, but they are full frame and I have always liked the appearance of these cars. But again, sh*tty brakes, suspension, etc. At least they have an 8.5" diff. Probably more work for the swap.)
I can spend upto $10k, and I guess I have somewhat decided on a C4. I have seen a few in Autotrader that seem decent. I don't need a show car. My question is, if I get a C4 with the L98 engine, would I gain alot, performance wise, by swapping in my engine?
p.s. sorry about my "simple" profile, still working on it.
Safety Car
Joined: Dec 2006
Posts: 4,290
Likes: 6
From: St Marys GA
L98s have around 250hp and 350 ftlb of tq stock. So yes, 400hp and, I'm assuming similar torque numbers, would be a nice improvement. Since you'll be replacing the engine/tranny anyway, you can probably find an early C4 for $5k or so. Maybe even less if you can find one without engine/tranny at all.
Thread Starter
Cruising
Joined: Dec 2006
Posts: 13
Likes: 0
From: Montreal Quebec
L98s have around 250hp and 350 ftlb of tq stock. So yes, 400hp and, I'm assuming similar torque numbers, would be a nice improvement. Since you'll be replacing the engine/tranny anyway, you can probably find an early C4 for $5k or so. Maybe even less if you can find one without engine/tranny at all.
Also, I believe that from 1987 on, the L98 came with a one piece rear seal, which has a different bolt pattern on the crank for the flywheel. Does this mean I would be limited to an 1984-1986, or could I just change the flywheel on a later (1987 and newer) C4? Isn't the 1 piece rear seal engine externally balanced vs the internally balanced 2 piece rear seal engine?
Last edited by mrl; Mar 1, 2008 at 05:56 PM.
Thread Starter
Cruising
Joined: Dec 2006
Posts: 13
Likes: 0
From: Montreal Quebec
I was thinking of just swapping the engine and leaving in the 4+3 or ZF6(nice to have an overdrive). Could these trannys handle the bhp/torque of my engine? Of course, the 400bhp is probably equivalent to, I'm guessing, 300 net hp.
Also, I believe that from 1987 on, the L98 came with a one piece rear seal, which has a different bolt pattern on the crank for the flywheel. Does this mean I would be limited to an 1984-1986, or could I just change the flywheel on a later (1987 and newer) C4? Isn't the 1 piece rear seal engine externally balanced vs the internally balanced 2 piece rear seal engine?
Also, I believe that from 1987 on, the L98 came with a one piece rear seal, which has a different bolt pattern on the crank for the flywheel. Does this mean I would be limited to an 1984-1986, or could I just change the flywheel on a later (1987 and newer) C4? Isn't the 1 piece rear seal engine externally balanced vs the internally balanced 2 piece rear seal engine?
So I guess if I get the earlier's C4 flywheel (1984-1986), bolt it to my gen I SBC, I could potentially install it into a post 1986 C4. Would a 1987-1991 clutch and pressure plate bolt on to the pre 1987 flywheel?
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Ask Tom at Carolina Clutch.. he will know and has a ton of different styles avaliable.
Are you keeping fuel injection? what are the particulars in the engine (to make sure its computer compatible)? Cam? heads have accessory holes in the front of them? (Old camel hump type heads wont work)
Are you keeping fuel injection? what are the particulars in the engine (to make sure its computer compatible)? Cam? heads have accessory holes in the front of them? (Old camel hump type heads wont work)
Burning Brakes
Joined: Aug 2000
Posts: 1,146
Likes: 2
From: Albuquerque NM
I have a first gen SBC built to around 400 bhp. I also have an m21 close ratio which I may or may not choose to use. I have been trying to figure out the "best" car for my engine. I am aware that "best" is very subjective, but I am looking for a car where the install will be relatively quick and simple. I have considered the following three possibilities. Please feel free to propose others. The car must be a manual shift.
1)1985-1992 C4
2)Third gen F-body (weak T5 and diff)
3)1983-1987 442 (I know the chassis s*cks, but they are full frame and I have always liked the appearance of these cars. But again, sh*tty brakes, suspension, etc. At least they have an 8.5" diff. Probably more work for the swap.)
I can spend upto $10k, and I guess I have somewhat decided on a C4. I have seen a few in Autotrader that seem decent. I don't need a show car. My question is, if I get a C4 with the L98 engine, would I gain alot, performance wise, by swapping in my engine?
p.s. sorry about my "simple" profile, still working on it.
1)1985-1992 C4
2)Third gen F-body (weak T5 and diff)
3)1983-1987 442 (I know the chassis s*cks, but they are full frame and I have always liked the appearance of these cars. But again, sh*tty brakes, suspension, etc. At least they have an 8.5" diff. Probably more work for the swap.)
I can spend upto $10k, and I guess I have somewhat decided on a C4. I have seen a few in Autotrader that seem decent. I don't need a show car. My question is, if I get a C4 with the L98 engine, would I gain alot, performance wise, by swapping in my engine?
p.s. sorry about my "simple" profile, still working on it.
The biggest issues/questions that you'll need to answer is fitment. Both the vette and later F-bodies will have clearance issues with certain intakes...measure wisely.
Additionally, the transmission for the vette do not bolt up using a cross member as other cars...so the M21 will be a $custom$ fit. If you come up with a tranny swap take plenty pictures and measurements so the forum can take advantage of your trail-blazin'
400HP isn't really that big of a deal once you consider the TPI intakes is worth -100 HP on TPI motors. Any decent Cam/valve train package will net the 400HP.
...so my suggestion is to go cool and go 442!
...If you are stuck on the vette, I'd go with a very high mile 90-91 or a C4 that needs a engine rebuild at a reduced cost. In the end you'll find that the long-block is a small percentage of $ and time for the corvette project.
Thread Starter
Cruising
Joined: Dec 2006
Posts: 13
Likes: 0
From: Montreal Quebec
Ask Tom at Carolina Clutch.. he will know and has a ton of different styles avaliable.
Are you keeping fuel injection? what are the particulars in the engine (to make sure its computer compatible)? Cam? heads have accessory holes in the front of them? (Old camel hump type heads wont work)
Are you keeping fuel injection? what are the particulars in the engine (to make sure its computer compatible)? Cam? heads have accessory holes in the front of them? (Old camel hump type heads wont work)
